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

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

2020-12-29
$$f(\theta)=\sin \theta$$ 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:
$$f(\theta+\pi)= -0.2$$

### Relevant Questions

Find the values of the other trigonometric functions of theta if $$\displaystyle{\cot{\theta}}=-\frac{{4}}{{3}}{\quad\text{and}\quad}{\sin{\theta}}{<}{0}$$.
Let theta be an angle in standard position, $$\displaystyle{\sin{\theta}}{<}{0},{\cos{\theta}}{>}{0}$$. Name the quadrant in which theta lies.
Find the derivative of
$$\displaystyle{y}={\sin{{\left(\pi{x}\right)}}}$$

sec theta = -3, tan theta > 0ZSK. Find the exact value of the remaining trigonometric functions of
thetaZSK.
Given the following information about one trigonometric function, evaluate the other five functions.
$$\displaystyle{\cos{{u}}}=\frac{{5}}{{13}}$$ , where $$\displaystyle{0}\le{u}\le\frac{\pi}{{2}}.$$
Use the figures to find the exact value of the trigonometric function $$\displaystyle{\tan{{2}}}\theta$$.
Sketch a right triangle corresponding to the trigonometric function of the acute angle theta. Use the Pythagorean Theorem to determine the third side and then find the other five trigonometric functions of theta. $$\displaystyle{\cos{\theta}}=\frac{{21}}{{5}}$$
$$y=\sin(\pi x)$$
A. $$\displaystyle{\sin{{A}}}={0.5}$$
B. $$\displaystyle{\sin{{A}}}={1.2654}$$
C. $$\displaystyle{\sin{{A}}}={0.9962}$$
Find derivative of trigonometric function $$\displaystyle{y}=\frac{{{3}{\left({1}-{\sin{{x}}}\right)}}}{{{2}{\cos{{x}}}}}$$