Trig function evaluations. $\frac{\cos^3 (\pi)}{3}$

Question

I know $\cos (\pi) = -1$. But the $\cos$ to the 3rd power is messing me up. I'm not sure what to do with that. Also, as a note, the entire function $\cos^3 (\pi)$ is divided by $3$.

Answer 1

The notation $\cos^3 x$ really means $(\cos x)^3$. So $\cos^3 \pi$ is just $(\cos\pi)^3 = (-1)^3 = -1$.

So your final answer should be $-1$ divided by 3, or in other words $-\frac{1}{3}$.