Connected Rates of Change (Edexcel A Level Maths): Revision Note
Did this video help you?
Connected Rates of Change
What are connected rates of change?
In situations involving more than two variables you can use the chain rule to connect multiple rates of change into a single equation

Equations involving derivatives (ie rates of changes) are known as differential equations
These can be solved using methods of integration (see Differential Equations )
However setting up the equation from the information given can involve the chain rule and connected rates of change
Note from the examples above that you will often need to differentiate a formula to get one of the rates of change you need
Examiner Tips and Tricks
These problems can involve a lot of letters – be sure to keep track of what they all refer to.
Be especially sure that you are clear about which letters are variables and which are constants – these behave very differently when differentiation is involved!
Worked Example

You've read 0 of your 5 free revision notes this week
Sign up now. It’s free!
Did this page help you?