Question

(f(x+h)-f(x))/h if f(x)=-2x^2

Answer 1

so its 1st principals...

f(x) = -2x^2 f(x + h) = -2(x + h)^2


so f(x +h) - f(x) = -2(x + h)^2 - -2x^2
------------ ------------------
h h

there is probably a limit as h ==> 0 or something like that

so distribute f(x + h) then collect like terms

look for a common factor that cancels fromt he numerator and denominator.

Answer 2

Why is f(x+h) equal to -2(x+h)^2?

Answer 3

f(x) = -2x^2 f(x+h) means substitute (x +h) where ever x occurs

its like

f(x) = 3x f(2) = 3*2 = 6