The Product Rule
If f and g are both differentiable. The Product Rule says that the derivative of the product of two functions is the first function times the derivative of the second function plus the second function times the derivative of the first function.
The Quotient Rule
If f and g are both differentiable. The Quotient rule says that the derivative of a quotient is the denominator times the derivative of the numerator, minus the numerator times the derivative of the denominator, all divided by the square of the denominator.