How do I solve (f(x-h)+f(x)/h) where f(x-h)=2x^2-4xh+2h^2-3 & f(x)=2x^2-3

Question

f(x-h)+f(x) =(2x²-4xh+2h²-3)+(2x²-3)

[f(x-h)+f(x)]/h=???

Answer 1

f(x-h)= 2x² - 4xh + 2h² -3 , f(x) = 2x² -3,

f(x-h)-f(x)/ h = [2x² - 4xh + 2h² -3 - (2x² - 3)] / h = (2x² - 4xh + 2h² -3 - 2x² + 3) / h = (-4xh + 2h²) / h

= h( -4x +2h) / h = -4x + 2h