Question

Find F(x+h)-f(x)/h if f(x)= 1/x

Answer 1

first find f(x+h) and tell,can u ?

Answer 2

1/(x+h)?

Answer 3

right,so u have\[\frac{\frac{1}{x+h}-\frac{1}{x}}{h}\]
right?
now cross-multiply.

Answer 4

How....?

Answer 5

\[\frac{\frac{1}{x+h}-\frac{1}{x}}{h}=\frac{x-(x+h)}{xh(x+h)}\]
got this?
whats numerator simplified to ?

Answer 6

Its simplified to x, how'd you move the h up.....

Answer 7

*h

Answer 8

i did not move h up,it was previously in the denominator,and still in the denominator.
\[\frac{\frac{a}{b}}{c}=\frac{a}{bc}\]
and the numerator would be -h. x-x-h=-h

Answer 9

Ahh okay. So whats the next step?

Answer 10

and is the a/b/c something I'll learn in calc?

Answer 11

do u see something common in num and denom. ?
if yes cancel that out and tell me what remains,
thats your final answer.
that a/b/c is a school stuff,which u should have known.....

Answer 12

I had a bad teacher for Pre-Calc.

Answer 13

so what u got after cancelling?

Answer 14

x(x+1) ?

Answer 15

-1/x(x+1)?

Answer 16

thats your final answer :)

Answer 17

Wait I was right?

Answer 18

u just missed h
-1/x(x+h)
is the final answer

Answer 19

grrr and thanks!

Answer 20

welcome :)