How do you find f'(x) using the definition of a derivative f(x) = x^2 + xf(x)=x2+x?
2 Answers
Jul 23, 2018
Explanation:
Recall that,
Jul 23, 2018
Explanation:
"differentiating from first principles"
f'(x)=lim_(hto0)(f(x+h)-f(x))/h
=lim_(hto0)((x+h)^2+x+h-x^2-x)/h
=lim_(hto0)(cancel(x^2)+2hx+h^2cancel(+x)+hcancel(-x^2)cancel(-x))/h
=lim_(hto0)(cancel(h)(2x+h+1))/cancel(h)
=2x+1