# Math Help - Evaluate

1. ## Evaluate

Given f(x) = cos x and g(x) = π/2, evaluate f(g(3)).

2. You don't even have to compose functions. Note that $g(\alpha)=\frac\pi2$ for every $\alpha\in\mathbb R,$ so $g(3)=\frac\pi2.$ Hence $f\big(g(3)\big)=f\left(\frac\pi2\right)=0.$