Can-you-pls-help-me-with-that-but-only-by-using-the-derivative-of-f-1-and-not-using-the-defined-defivative-of-f-x-itself-Thanks-f-x-x-2-x-f-1-

Question Number 52953 by hassentimol last updated on 15/Jan/19

Can you pls help me with that but only

by using the derivative of f (1) and not

using the defined defivative of f (x) itself ?

Thanks

f (x) = x^{2} - x

f^{'} (1) = ?

Answered by tanmay.chaudhury50@gmail.com last updated on 15/Jan/19

f^{^{'}} (1) = \lim_{h \to 0} \frac{{{(1 + h)}^{2} - (1 + h)} - {1^{2} - 1}}{h}

= \lim_{h \to 0} \frac{1 + 2 h + h^{2} - 1 - h}{h}

= \lim_{h \to 0} \frac{h (1 + h)}{h}

= 1 + 0 = 1 a n s

Commented by hassentimol last updated on 15/Jan/19

I am so grateful to you! I was asking myself

why my answer was incorrect and now,

thans to you, I am understamding!

Commented by tanmay.chaudhury50@gmail.com last updated on 15/Jan/19

f^{,} (a) = \lim_{h \to 0} \frac{f (a + h) - f (a)}{h} t h i s i s f o r m u l a

\dots t h a n k y o u \dots