Question

Find the exact value of cos 150 degrees and sin 150 degrees

Answer 1

(a)

`cos(150)`

we know that

`150=180-30`

`cos(150)=cos(180-30)`

`cos(150)=-cos(30)`

now, we can use unit circle

and we get

`cos(150)=-(√(3))/(2)`...........Answer

(b)

`sin(150)`

we know that

`150=180-30`

`sin(150)=sin(180-30)`

`sin(150)=sin(30)`

now, we can use unit circle

and we get

`sin(150)=(1)/(2)`...........Answer