Question

How do you find f'(x) using the definition of a derivative for `f(x)= -7x^2 + 4x`?

Answer 1

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Explanation:

It is

#f'(x)=lim_(h->0) ((f(x+h)-f(x))/h) => f'(x)=lim_(h->0)(-7*(x+h)^2+4(x+h)-(-7x^2+4x))/h=> f'(x)=lim_(h->0) ((-h(7h+2*(7x-2)))/h)=> f'(x)=lim_(h->0) (-(7h+2(7x-2)))=> f'(x)=-14x+4#