Question

Difference quotient:
f(x)=3-4x-x^2

(f(f+h)-f(5))/h

=3-4(5+h)-(5+h)^2 +8
=-42-h-10h-h^2+8
=-34-11h-h^2
=-45-h

I feel like I probably went wrong somewhere...

Answer 1

you didn't subtract f(5) properly from f(x+h). also remember that at the end you divide everything by h

Answer 2

and it's the limit as h->0 of this