P (a) = 2a+2; Find p (a^2)

No matter what variables you use, the idea remains the same: with functions, you take your input - here a, and apply something to it - 2a + 2. Here, your input is a². We put a² in for a. It might look strange at first - you put a variable in, not a number, but anything can go in a function and come out on the other side of the equals sign. The function does the same thing (s) as before.

P (a) = 2a + 2

P (a²) = 2a² + 2

Notice how the a and a-squared pieces match up but the numbers and + stay the same.

Thus, P (a²) = 2a² + 2