1. ## Difference quotient

F(x)= sqrt (x+1).

Formula: F(x+h) - F(x) / h

2. Originally Posted by lsnyder
F(x)= sqrt (x+1).

Formula: F(x+h) - F(x) / h

chances are your problem lies in finding f(x + h)

post what you think it is

3. i keep writing out to this:

sqrt(x+h+1) - sqrt(x+1) / h.

after that i get lost and come up with random answers

4. Originally Posted by lsnyder
i keep writing out to this:

sqrt(x+h+1) - sqrt(x+1) / h.

after that i get lost and come up with random answers
ok, good so far. from here, the trick is to multiply by the conjugate of the numerator over itself, then simplify

$\displaystyle \frac {\sqrt{x + h + 1} - \sqrt{x + 1}}h \cdot \frac {\sqrt{x + h + 1} + \sqrt{x + 1}}{\sqrt{x + h + 1} + \sqrt{x + 1}}$

can you take it from here?

5. so is it:

x+h+1-x-1 / (h sqrt(x+h+1) + sqrt(x+1)

this doesn't look right to me. and this is online homework, which i keep getting the wrong answer

6. Originally Posted by lsnyder
so is it:

x+h+1-x-1 / (h sqrt(x+h+1) + sqrt(x+1)

this doesn't look right to me. and this is online homework, which i keep getting the wrong answer
well, if you type it here like you type it there, of course you're wrong. you have incorrect use of parentheses here. (and not that the numerator simplifies to h--which cancels with the h in the denominator)

7. can u see this? if so, its the original problem, it might make more sense

8. Originally Posted by lsnyder

can u see this? if so, its the original problem, it might make more sense
nope, can't see anything

9. okay well thanks for trying anyways.

10. Originally Posted by lsnyder
okay well thanks for trying anyways.
just try to simplify from where you left off, and get your parentheses right