How do you find the exact value of a trigonometric ratio?

Simplify the expression. enter the correct answer.

Suppose that the function f is defined. , for all real numbers, as follows. _ \ 1/4x² -4 if x≠ -2 f(x)=< /_-1 if x=-2 find f(-5), f(-2), and f(4)

At a book fair, joe bought 24 books at 3 for $5 and had $2 left. how much money did he have at first?