use the definition of the derivative f'(x)=lim x-delta x of (f(x+delta x)-f(x))/delta x of f(x)=2/(x-5)

Question

use the definition of the derivative f'(x)=lim x->delta x of (f(x+delta x)-f(x))/delta x of f(x)=2/(x-5)

watchmath · Answer

sorry , why I post that on your question? ?

watchmath · Answer

ignore that! there was a but on this software

watchmath · Answer

but =bug

anonymous · Answer

alright

watchmath · Answer

Then I oblige to answer your question :). For $f(x)=2/(x-5)$. The expression become 
$$\frac{1}{\Delta x}(2/(x+\Delta x -5)-2/(x-5))=\frac{-2\Delta x}{\Delta x(x-5)(x+\Delta x-5)}=\frac{-2}{(x-5)(x+\Delta x-5)}$$
As $\Delta x\to 0$ we have $-2/(x-5)^2$.

anonymous · Answer

for some reason i cant see past the second equals sign... :/

watchmath · Answer

Try to refresh the browser. Press F5.

anonymous · Answer

nope still the same thing. and i have a mac. so i dont have f5...

watchmath · Answer

See the attachment.