Question

Given the function f(x)=x2+2x+1, find: f(2b)

Answer 1

I will do the first one only. The second question is done the same way.

Replace every x you see in the function with 2b and do the math.

f(x) = x^2 + 2x + 1

Let x = 2b

f(2b) = (2b)^2 + 2(2b) + 1

f(2b) = 4b^2 + 4b + 1

Did you follow? That's all there is to it.