Question

Can someone please explain this to me please

Answer 1

-3(x + h)^2 + 5(x + h) + 4

-3(x^2 + 2xh + h^2) + 5(x + h) + 4

-3x^2 - 6xh - 3h^2 + 5x + 5h + 4

Now apply the Difference Quotient:

(-3x^2 - 6xh - 3h^2 + 5x + 5h + 4 - (-3x^2 + 5x + 4)) / h =

(-6xh - 3h^2 +5h) / h = -6x - 3h + 5

Answer 2

Explanation:

First calculate: f (x+h) = -3 (x+h)^2 + 5 ( x+h) + 4 then expand :

- 3x^2 -6 xh - 3 h^2 + 5x + 5h + 4

Now subtract f(x) ....and divide the whole thing by h

[ -3x^2 - 6 xh - 3h^2 + 5x + 5h + 4 - ( -3x^2 + 5x +4) ] / h

= (- 6xh - 3h^2 + 5h ) / h

= -6x - 3h+ 5 <===== difference quotient