Question

Simplify the trigonometric expression. cos(theta+pi/2)

Answer 1

We have to simplify the expression:

`\cos (\theta+(\pi)/(2))`

We could see it graphically:

We see that for any angle theta, the cosine of theta + pi/2 is equal to negative sin of theta.

Then we can write:

`\cos (\theta+(\pi)/(2))=-\sin (\theta)`

The answer is -sin(theta).