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f(c) means let x=c. Remember that c is just an unknown number.

The expression f(c)=9 means that when we put c through the function f(x)=7-4x, it gives the answer 9. Therefore we know 7-4c...

Firstly, we calculate the y-value when x=1, namely y=e. Then we need to find the gradient of this curve at x=1, which can be determined by taking the derivative of y and then valuate it at x=1. So dy/d...

Four mark questions are a great way to pick up marks. There is a simple strategy to remember when answering these. 

Firstly, always write down your definition of the key word(s). Even if ...

In your exams and your essays in general, when asked to analyse unseen texts, your goal is to show a sophisticated reading and response. This can be quite difficult if you're not sure what to look for, if...

There are two ways in which this we can do this,

The first is explanding the brackets to get 1+2x+x² and differentiating to get 2+2x.

The second way is using the ...