find the expression for: (f(x+h))-(f(x)))/h given: f(x)=-pix^2-pi^2
simplify far enough that plugging in h = 0 would be allowed
f(x)= -πx^2 - π^2 , remember π is just a constant
(f(x+h) - f(x) )/h
= (-π(x+h)^2 - π^2 - (-πx^2 - π^2) )/h
= (-πx^2 - 2πxh - πh^2 - π^2 + πx^2 + π^2)/h
= (-2πxh - πh^2 )/h
= -2πx - πh , h ≠ 0