To find the derivative of the quotient of two functions you use
Differentation rule 7 (quotient rule):
If (with g(x) ≠ 0) then .
Function is the numerator of the fraction, function is the denominator of the fraction.
You may not always need this differentiation rule. Sometimes you can simplify a quotient.
This rule is often used in combination with the previous differentiation rules.
Especially in combination with the chain rule!