The quotient rule is not all that simple but it can be a good solution when no simpler ones appear obvious.
When you have a function which can be represented by one function of x divided by another, the quotient rule tells us that the derivative of our original function is equal to:
One over the divisor function squared times the following quantity: the derivative of the numerator function times the divisor function minus the numerator function times the derivative of the divisor function.
