If we express \(x^2 + 4x + 5\) in the form \(a(x - h)^2 + k\), then what is h?
x2 + 4x + 5
Add and subtract (4/2)2 , which is 4 , to the expression.
= x2 + 4x + 4 + 5 - 4
Now factor the first three terms as a perfect square trinomial.
= (x + 2)2 + 5 - 4
= 1(x - -2)2 + 1
So a = 1 , h = -2 , and k = 1 .
