Question

Let f(x) = x^2 − 5. Find f(-3)

Answer 1

f(-3) = 4

Explanation:

f(x) = x² - 5

f(x) is a function with input x, meaning it is an expression which has terms involving x;

x is a variable and can be considered a space holder;

f(-3) is the function with input -3, this simply means replacing the space holder, i.e. x, with -3;

f(-3) = (-3)² - 5

f(-3) = 9 - 5

f(-3) = 4

Answer 2

f(-3)=4

Explanation:

Substitute x=-3 into the function

f(-3)=(-3)^2-5

f(-3)=9-5

f(-3)=4