Question

Sendo f(x)=x², calcule: f(x+h)-f(x)

Answer 1

$<var>f(x+h)-f(x)=\\ (x+h)^2-x^2=\\ x^2+2xh+h^2-x^2=\\ h^2+2hx</var>$

Answer 2

$<var>x^2+2xh+h^2-x^2=\\ 2hx+h^2=\\\\ h(2x+h)</var>$