The expression (x+h)3−x3h\frac{(x+h)^3 - x^3}{h}h(x+h)3−x3 (for h≠0h \neq 0h=0) simplifies to:
3x2+3xh+h23x^2 + 3xh + h^23x2+3xh+h2
3x23x^23x2
x2+xh+h2x^2 + xh + h^2x2+xh+h2
3x2h3x^2h3x2h