Core 1: Given that y = x^4 + x^2+3. Find dy/dx

First what we need to do is we need to think of what the question is asking us to find. In this case it is dy/dx but what is this. This is the rate of change of y with respect to x.  For understanding purposes: To do this what we want to do is use our formal definition of a derivative with our limit as h tends to 0 for (f(x+h)-f(x))/h. We can then sub in our equation into this and find our answer. 

Quicker Method: dy/dx of x^n=nx^n-1. We can then do this to every part of our function y to get an answer of 4x^3 +2x

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Answered by David S. Maths tutor

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