When we are forced to derive something like:

__dy__ __9x__^{2}

dx 3x

We could divide this out or re-write it to allow us to use the product rule, but the simplest way is to use what is called the quotient rule:

(*f*/*g*)'(x) = *g*(x)*f*'(x)-*f*(x)*g*'(x)
(*g*(x))^{2}

All this means is that we

**{**(multiply the

denominator with the derivative of the

numerator), subtract the product of (the

numerator and the

derivative of the denominator)

**}** and divide all this mess by the

**{**square of the denominator

**}**.