Question

If f(x)=sin xandf(a)=$\frac{3}{5}$, findf(-a)

Short answer

f(-a)=$\frac{-3}{5}$

Step-by-step solution

Step 1. Given information

f(x)=sin x

f(a) =$\frac{3}{5}$

Step 2. Solving for a 

Given$$\begin{gathered} f\left(a\right)=\frac{3}{5} \\ \Rightarrow a=37° \end{gathered}$$

Step 3. Solving of f(-a)

$$\begin{gathered} f(-a)=f(-37°)=\sin (-37°) \\ \left\{\sin \right(-x)=-\sin x\} \\ \Rightarrow f(-a)=\frac{-3}{5} \end{gathered}$$