Cho đồ thị hàm số $f'\left(x\right)$ như hình vẽ, hàm số $y=f\left(x\right)$ đồng biến trên khoảng nào dưới đây?

Cho đồ thị hàm số $f'\left(x\right)$ như hình vẽ, hàm số $y=f\left(x\right)$ đồng biến trên khoảng nào dưới đây?

Hàm số $y=x^3-3x^2-9x+1$ đồng biến trên khoảng nào dưới đây?

Hàm số $y=\sqrt{81-x^2}$ nghịch biến trên khoảng nào dưới đây?

Cho hàm số $y=f(x)$ có đồ thị như hình vẽ sau:

Hàm số đã cho nghịch biến trong khoảng nào dưới đây?

Cho hàm số $y=f(x)$ có bảng biến thiên như sau:

@bbt3(p.ty,[Math.min(p.x1,p.x2),f1(Math.min(p.x1,p.x2)),Math.max(p.x1,p.x2),f1(Math.max(p.x1,p.x2))])@

Hàm số $y=f(x)$ @qu[p.t]@ trong khoảng nào dưới đây?

+ p.khoang[2] + '; p.o[1] = ' + p.khoang[1] + '; p.o[2] = '$(' + Math.min(p.x1, p.x2) + ' ; +∞); p.o[3] = '$(-&#8734 ; ' + Math.max(p.x1, p.x2) + '); } else if ((p.a > 0 && p.t ==1) || (p.a < 0 && p.t ==0)) { p.o[0] = ' + p.khoang[1] + '; p.o[1] = ' + p.khoang[0] + '; p.o[2] = '$(' + Math.min(p.x1, p.x2) + ' ; +∞); p.o[3] = '$(-&#8734 ; ' + Math.max(p.x1, p.x2) + '); } function f1(x){return x*x}; function bbt3(type,bien){ var x1 = bien[0], x2 = bien[2], y1 = bien[1], y2 = bien[3]; switch(type){ case 1: // hàm bậc 3 có y` >= 0, y = 0 tại x = 0 return '<svg width="453" height="192" xmlns="http://www.w3.org/2000/svg"> <line stroke="#000" stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_1" y2="174.25423" x2="89" y1="23.24996" x1="89" stroke-width="1.5" fill="none"/> <line stroke="#000" stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_2" y2="60.24955" x2="394.01381" y1="60.24955" x1="49.99922" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" fill="none"/> <line stroke="#000" stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_3" y2="100.24968" x2="394.01381" y1="100.24968" x1="49.99922" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" fill="none"/> <line stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_14" y2="110.24971" x2="358.00022" y1="169.2499" x1="124.99947" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" stroke="#000" fill="none"/> <text xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_4" y="52.24953" x="60.99927" fill-opacity="null" stroke-opacity="null" stroke-width="0" stroke="#000" fill="#000000">x</text> <text xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_5" y="90.24965" x="60.99927" fill-opacity="null" stroke-opacity="null" stroke-width="0" stroke="#000" fill="#000000">y&apos;</text> <text xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_6" y="139.24981" x="60.99927" fill-opacity="null" stroke-opacity="null" stroke-width="0" stroke="#000" fill="#000000">y</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_7" y="52.24953" x="100.9994" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">-∞</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_8" y="52.24953" x="365.00025" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">+∞</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_10" y="53.24953" x="230.99982" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">0</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_11" y="92.24966" x="230.99982" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">0</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_12" y="174.24992" x="98.99939" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">-∞</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_13" y="116.24973" x="365.00025" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">+∞</text> <text transform="rotate(-20 354.5,110.73437500000006) " xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_15" y="118.24974" x="348.00019" fill-opacity="null" stroke-opacity="null" stroke="#000" fill="#000000">&gt;</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_16" y="92.24966" x="160.99959" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">+</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_17" y="92.24966" x="303.00005" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">+</text> </svg>'; case 11: // hàm bậc 3 có y` > 0 mọi x return '<svg width="453" height="192" xmlns="http://www.w3.org/2000/svg"> <line fill="none" stroke-width="1.5" x1="89" y1="23.24996" x2="89" y2="174.25423" id="svg_1" stroke-linejoin="undefined" stroke-linecap="undefined" stroke="#000"/> <line fill="none" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="49.99922" y1="60.24955" x2="394.01381" y2="60.24955" id="svg_2" stroke-linejoin="undefined" stroke-linecap="undefined" stroke="#000"/> <line fill="none" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="49.99922" y1="100.24968" x2="394.01381" y2="100.24968" id="svg_3" stroke-linejoin="undefined" stroke-linecap="undefined" stroke="#000"/> <line fill="none" stroke="#000" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="124.99947" y1="169.2499" x2="358.00022" y2="110.24971" id="svg_14" stroke-linejoin="undefined" stroke-linecap="undefined"/> <text fill="#000000" stroke="#000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="60.99927" y="52.24953" id="svg_4" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">x</text> <text fill="#000000" stroke="#000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="60.99927" y="90.24965" id="svg_5" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">y&apos;</text> <text fill="#000000" stroke="#000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="60.99927" y="139.24981" id="svg_6" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">y</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="100.9994" y="52.24953" id="svg_7" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">-∞</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="365.00025" y="52.24953" id="svg_8" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">+∞</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="98.99939" y="174.24992" id="svg_12" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">-∞</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="365.00025" y="116.24973" id="svg_13" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">+∞</text> <text fill="#000000" stroke="#000" stroke-opacity="null" fill-opacity="null" x="348.00019" y="118.24974" id="svg_15" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" transform="rotate(-20 354.5,110.73437500000006) ">&gt;</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="230.99959" y="92.24966" id="svg_16" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">+</text> </svg>'; case 2: // hàm bậc 3 có y` <=0, y = 0 tại x = 0 return '<svg width="453" height="192" xmlns="http://www.w3.org/2000/svg"> <line fill="none" stroke-width="1.5" x1="89" y1="23.24996" x2="89" y2="174.25423" id="svg_1" stroke-linejoin="undefined" stroke-linecap="undefined" stroke="#000"/> <line fill="none" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="49.99922" y1="60.24955" x2="394.01381" y2="60.24955" id="svg_2" stroke-linejoin="undefined" stroke-linecap="undefined" stroke="#000"/> <line fill="none" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="49.99922" y1="100.24968" x2="394.01381" y2="100.24968" id="svg_3" stroke-linejoin="undefined" stroke-linecap="undefined" stroke="#000"/> <text fill="#000000" stroke="#000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="60.99927" y="52.24953" id="svg_4" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">x</text> <text fill="#000000" stroke="#000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="60.99927" y="90.24965" id="svg_5" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">y&apos;</text> <text fill="#000000" stroke="#000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="60.99927" y="139.24981" id="svg_6" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">y</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="100.9994" y="52.24953" id="svg_7" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">-∞</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="365.00025" y="52.24953" id="svg_8" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">+∞</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="230.99982" y="53.24953" id="svg_10" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">0</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="230.99982" y="92.24966" id="svg_11" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">0</text> <text style="cursor: move;" fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="98.99939" y="116.24992" id="svg_12" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">+∞</text> <text style="cursor: move;" fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="365.00025" y="166.24973" id="svg_13" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">-∞</text> <text fill="#000000" stroke="#000" stroke-opacity="null" fill-opacity="null" x="351.00019" y="169.24974" id="svg_15" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" transform="rotate(13 357.5000000000002,161.734375) ">&gt;</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="160.99959" y="90.24966" id="svg_16" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">-</text> <text style="cursor: move;" fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="303.00005" y="90.24966" id="svg_17" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">-</text> <line stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_9" y2="162.4375" x2="361" y1="110.4375" x1="132" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" stroke="#000" fill="none"/> </svg>'; case 21: // hàm bậc 3 có y` < 0 mọi x return '<svg width="453.00000000000006" height="192" xmlns="http://www.w3.org/2000/svg"> <line stroke="#000" stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_1" y2="174.25423" x2="89" y1="23.24996" x1="89" stroke-width="1.5" fill="none"/> <line stroke="#000" stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_2" y2="60.24955" x2="394.01381" y1="60.24955" x1="49.99922" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" fill="none"/> <line stroke="#000" stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_3" y2="100.24968" x2="394.01381" y1="100.24968" x1="49.99922" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" fill="none"/> <text xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_4" y="52.24953" x="60.99927" fill-opacity="null" stroke-opacity="null" stroke-width="0" stroke="#000" fill="#000000">x</text> <text xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_5" y="90.24965" x="60.99927" fill-opacity="null" stroke-opacity="null" stroke-width="0" stroke="#000" fill="#000000">y&apos;</text> <text xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_6" y="139.24981" x="60.99927" fill-opacity="null" stroke-opacity="null" stroke-width="0" stroke="#000" fill="#000000">y</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_7" y="52.24953" x="100.9994" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">-∞</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_8" y="52.24953" x="365.00025" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">+∞</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_12" y="174.24992" x="368.16606" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">-∞</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_13" y="116.24973" x="95.00025" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">+∞</text> <text transform="rotate(13 357.5833740234375,168.23439025878906) " xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_15" y="175.74974" x="351.33352" fill-opacity="null" stroke-opacity="null" stroke="#000" fill="#000000">&gt;</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_16" y="92.24966" x="230.99959" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">-</text> <line stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_9" y2="169.4375" x2="362" y1="111.4375" x1="127" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" stroke="#000" fill="none"/> </svg>'; case 3: // hàm bậc 3, a> 0 y` có hai nghiệm return '<svg width="504.00000000000006" height="192" xmlns="http://www.w3.org/2000/svg"> <line fill="none" stroke-width="1.5" x1="89" y1="23.24996" x2="89" y2="184.73045" id="svg_1" stroke-linejoin="undefined" stroke-linecap="undefined" stroke="#000"/> <line fill="none" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="49.99922" y1="60.24955" x2="473.06155" y2="60.24955" id="svg_2" stroke-linejoin="undefined" stroke-linecap="undefined" stroke="#000"/> <line fill="none" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="49.99922" y1="100.24968" x2="474.014" y2="100.24968" id="svg_3" stroke-linejoin="undefined" stroke-linecap="undefined" stroke="#000"/> <line fill="none" stroke="#000" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="130.57142" y1="169.7502" x2="217.23832" y2="121.17864" id="svg_21" stroke-linejoin="undefined" stroke-linecap="undefined"/> <line stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_9" y2="171.24703" x2="328.66689" y1="115.4375" x1="260.09586" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" fill="none" stroke="#000"/> <line stroke="#000" fill="none" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="370.57142" y1="171.7502" x2="441.23832" y2="125.17864" id="svg_17" stroke-linejoin="undefined" stroke-linecap="undefined"/> <text fill="#000000" stroke="#000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="60.99927" y="52.24953" id="svg_4" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">x</text> <text fill="#000000" stroke="#000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="60.99927" y="90.24965" id="svg_5" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">y&apos;</text> <text fill="#000000" stroke="#000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="60.99927" y="139.24981" id="svg_6" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">y</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="100.9994" y="52.24953" id="svg_7" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">-∞</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="439.28616" y="52.24953" id="svg_8" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">+∞</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="220.5236" y="89.39251" id="svg_11" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">0</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="442.99939" y="116.24992" id="svg_12" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">+∞</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="99.76237" y="183.63071" id="svg_13" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">-∞</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="168.30122" y="87.28673" id="svg_16" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">+</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="221.47599" y="53.24953" id="svg_10" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">'+ x1 +'</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="221.47599" y="119.91653" id="svg_19" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">'+ y1 +'</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="345.28583" y="53.24953" id="svg_14" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">'+ x2 +'</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="343.28583" y="180.0116" id="svg_20" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">'+ y2 +'</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="345.28583" y="88.48772" id="svg_18" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">0</text> <text transform="rotate(-35 213.90429687499997,122.12055969238281) " fill="#000000" stroke="#000" stroke-opacity="null" fill-opacity="null" x="207.71448" y="129.7501" id="svg_22" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">&gt;</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="292.00367" y="87.28673" id="svg_25" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">-</text> <text fill="#000000" stroke-width="0" stroke-opacity="null" fill-opacity="null" x="409.78025" y="87.28673" id="svg_26" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" stroke="#000">+</text> <text fill="#000000" stroke="#000" stroke-opacity="null" fill-opacity="null" x="320.57184" y="177.10689" id="svg_15" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve" transform="rotate(39 327.0624999999999,169.59375000000006) ">&gt;</text> <text transform="rotate(-35 439.20312499999994,126.25) " fill="#000000" stroke="#000" stroke-opacity="null" fill-opacity="null" x="432.71448" y="133.7501" id="svg_23" font-size="22" font-family="Katex_Math, Times, serif" text-anchor="start" xml:space="preserve">&gt;</text> </svg>'; case 4: // hàm bậc 3, a< 0 y` có hai nghiệm return '<svg width="504.00000000000006" height="192" xmlns="http://www.w3.org/2000/svg"> <line stroke="#000" stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_1" y2="184.73045" x2="89" y1="23.24996" x1="89" stroke-width="1.5" fill="none"/> <line stroke="#000" stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_2" y2="60.24955" x2="473.06155" y1="60.24955" x1="49.99922" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" fill="none"/> <line stroke="#000" stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_3" y2="100.24968" x2="474.014" y1="100.24968" x1="49.99922" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" fill="none"/> <line stroke="#000" fill="none" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="132" y1="110.4375" x2="209.57103" y2="166.24703" id="svg_9" stroke-linejoin="undefined" stroke-linecap="undefined"/> <line stroke-linecap="undefined" stroke-linejoin="undefined" id="svg_21" y2="121.17864" x2="337.23832" y1="169.7502" x1="250.57142" fill-opacity="null" stroke-opacity="null" stroke-width="1.5" stroke="#000" fill="none"/> <line stroke="#000" fill="none" stroke-width="1.5" stroke-opacity="null" fill-opacity="null" x1="370.09586" y1="110.4375" x2="447.66689" y2="166.24703" id="svg_24" stroke-linejoin="undefined" stroke-linecap="undefined"/> <text xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_4" y="52.24953" x="60.99927" fill-opacity="null" stroke-opacity="null" stroke-width="0" stroke="#000" fill="#000000">x</text> <text xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_5" y="90.24965" x="60.99927" fill-opacity="null" stroke-opacity="null" stroke-width="0" stroke="#000" fill="#000000">y&apos;</text> <text xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_6" y="139.24981" x="60.99927" fill-opacity="null" stroke-opacity="null" stroke-width="0" stroke="#000" fill="#000000">y</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_7" y="52.24953" x="100.9994" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">-∞</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_8" y="52.24953" x="439.28616" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">+∞</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_11" y="89.39251" x="220.5236" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">0</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_12" y="116.24992" x="98.99939" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">+∞</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_13" y="185" x="449.76237" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">-∞</text> <text transform="rotate(39 207.66928100585926,164.47988891601562) " xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_15" y="172.10689" x="201.47598" fill-opacity="null" stroke-opacity="null" stroke="#000" fill="#000000">&gt;</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_16" y="87.28673" x="168.30122" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">-</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_10" y="53.24953" x="221.47599" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">'+ x1 +'</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_19" y="185.91653" x="210.47599" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">'+ y1 +'</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_14" y="53.24953" x="345.28583" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">'+ x2 +'</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_20" y="118.0116" x="345.28583" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">'+ y2 +'</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_18" y="88.48772" x="345.28583" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">0</text> <text transform="rotate(-35 333.90429687500006,122.1205596923829) " xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_22" y="129.7501" x="327.71448" fill-opacity="null" stroke-opacity="null" stroke="#000" fill="#000000">&gt;</text> <text transform="rotate(39 445.76513671875006,164.47988891601568) " xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_23" y="172.10689" x="439.57184" fill-opacity="null" stroke-opacity="null" stroke="#000" fill="#000000">&gt;</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_25" y="87.28673" x="280.00367" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">+</text> <text stroke="#000" xml:space="preserve" text-anchor="start" font-family="Katex_Math, Times, serif" font-size="22" id="svg_26" y="87.28673" x="409.78025" fill-opacity="null" stroke-opacity="null" stroke-width="0" fill="#000000">-</text> </svg>'; }; }

Hàm số $y=f(x)$ có bảng biến thiên như sau:

Trong các khẳng định nào dưới đây, khẳng định nào đúng?

Cho hàm số $y=x^4-2x^2+3,$ khẳng định nào sau đây đúng?

Cho hàm số $y=f(x)$ có đồ thị như hình vẽ:

Hàm số đã cho nghịch biến trong khoảng nào dưới đây?

Trong các hàm số sau, hàm số nào đồng biến trên khoảng $ℝ?$

Cho hàm số $y=f\left(x\right)$có đồ thị như hình dưới. Khẳng định nào sau đây đúng?

Hàm số $y=-x^2+2x-3$ nghịch biến trên khoảng nào dưới đây?

Cho hàm số $y=f\left(x\right)$ có đạo hàm $y'>0$ với mọi $x\ne-1,$ khẳng định nào sau đây đúng?

Cho hàm số $y=f\left(x\right)$ có bảng biến thiên như hình vẽ, hàm số nghịch biến trên khoảng nào dưới đây?