Question

did i get the right answer? (file attached)

Answer 1

or is the answer x+5?

Answer 2

hey smurfy
f(x+h)-f(x)=[(x+h)^3-1]-[x^3-1]
=x^3+3x^2h+3xh^2+h^3-1-x^3+1
=3x^2h+3xh^2
=3xh(x+h)
(but h=x+3)
so
=3x(x+3)(x+(x+3))
=3x(x+3)(2x+3)

Answer 3

=3x(2x^2+3x+6x+9)
=3x(2x^2+9x+9)
=6x^3+27x^2+27x

Answer 4

oh ok thanks myininaya :)