How do you find the gradient of the tangent to the curve $y=x^3$ at the given value of x=4?

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Answer 1 · 2015-04-03T21:22:47

You start by evaluating the derivative $y'$ of the function and then substitute $x=4$ in it:

$y'(x)=3x^2$

substitute $x=4$ ;

$y'(4)=3*4^2=48$ which is your gradient.

How do you find the gradient of the tangent to the curve y=x^3y=x^3 at the given value of x=4?