What is the quotient rule?
- The quotient rule is a formula that allows you to differentiate a quotient of two functions (ie one function divided by another)
- If where u and v are functions of x then the quotient rule is:
- In function notation, if then the quotient rule can be written as:
- The quotient rule formula is in the formulae booklet – you don't have to memorise it.
- Be careful using the formula – because of the minus sign in the numerator the order of the functions is important.
- Look out for functions of the form
- You could differentiate that using a combination of the chain rule and the product rule (and it can be good practice for you to try it!)
- But it can also be seen as just a quotient rule question in disguise