Question

if cos 3x is zero x acute find the value of sin x and Cos 2x

Answer 1

Answer is 1/2 for both (cos3x=0, so we can write 3x=cos inverse0, then using inverse trigonometry 3x= pie/2, and x=pie/6 now substitute in six and cos2x we get 1/2 as the right answer.

Answer 2

Answer

cos3x=0=cos90

3x=90

x=30.

sin x=sin30=1/2

Cos2x=cos60=1/2