Question

Evaluate f(a + h) − f(a) for the quadratic function f(x) = x2 + 5. f(a + h) − f(a)

Answer 1

`f(x)=x^2+5\\\\f(a+h)=(a+h)^2+5=a^2+2ah+h^2+5\\\\f(a)=a^2+5\\\\f(a+h)-f(a)=(a^2+2ah+h^2+5)-(a^2+5)=a^2+2ah+h^2-a^2-5=2ah+h^2`