a: Ta có: \(\sin^2a+cos^2a=1\)

=>\(cos^2a=1-0,6^2=0,64=0,8^2\)

=>cosa=0,8

\(\tan a=\frac{\sin a}{cosa}=\frac{0.6}{0.8}=\frac34\)

\(\cot a=\frac{1}{\tan a}=1:\frac34=\frac43\)

\(\sin\left(90^0-a\right)=cosa=0,8\)

\(cos\left(90^0-a\right)=\sin a=0,6\)

b: \(\sin^2a+cos^2a=1\)

=>\(sin^2a=1-\left(\frac{1}{\sqrt5}\right)^2=1-\frac15=\frac45\)

=>\(\sin a=\frac{2}{\sqrt5}\)

tan a=\(\frac{\sin a}{cosa}=\frac{2}{\sqrt5}:\frac{1}{\sqrt5}=2\)

cot a=1/tana=1/2

\(\tan\left(90^0-a\right)=\cot a=\frac12\)

\(\cot\left(90^0-a\right)=\tan a=2\)

Ban can cau nao nhi?

làm bài nào??

The due date for the final paper has passed; therefore, I could not submit mine on time.

There are many history books; however, none of them may be accurate.

It rained hard; moreover, lightening flashed and thunder boomed.

The baby fell asleep; then, the doorbell rang.

The law does not permit drinking and driving anytime; otherwise, there would be many more accidents.

1, That
2, This
3, that
4, those
5, these - that
6, these
7, this
8, that
9, that
10, this
11, those
12, this
13, it
14, these
15, them

16, those

this/that dùng cho ng, vật số ít

this: dùng cho ng, vật ở gần

that: dùng cho ng, vật ở xa

these/those dùng cho ng, vật số nhiều

these: ở gần

those: ở xa