Question

# If f(theta) = sin theta = 0.2 Find f(theta + pi)

Trigonometric Functions
If $$f(\theta) = \sin \theta = 0.2$$
Find $$f(\theta + \pi)$$

$$f(\theta)=\sin \theta$$ has a period of $$2\pi$$ such that consecutive half-period values have the same absolute values but alternate in sign.
Since $$f(\theta+\pi)$$ means the value of $$f(\theta)$$ after a half-period, then we only take the opposite of its value:
$$f(\theta+\pi)= -0.2$$