I'm taking College algebra and I don't know how to do this problem: f (x) = (x-2) ^2 + 4

You must know that : (a-b) ^2 = a^2 - 2ab + b^2 so let a=x and b=2, applying above formula you'll get f (x) = x^2 - 4x + 4 + 4 = x^2 - 4x + 8 Hope you got it; - ) Revert back if you still face any trouble.