# Thread: Evaluating functions

1. ## Evaluating functions

hello,
can someone answer and explain in detail the following question:

(Q) Evaluate the function

f(x)=x/
sqrt x +1 -1

at the points x = -0.01, -0.001, 0, 0.001, 0.0

-the answers should be:
1.99499 1.9996 ? 2.00050 2.00499
what i would like to know is how?

2. Originally Posted by ethio
hello,
can someone answer and explain in detail the following question:

(Q) Evaluate the function

f(x)=x/
sqrt x +1 -1

at the points x = -0.01, -0.001, 0, 0.001, 0.0

-the answers should be:
1.99499 1.9996 ? 2.00050 2.00499
what i would like to know is how?
You will need to be much clearer in what the function is. Is it $f(x) = \frac{x}{\sqrt{x + 1}} - 1 ?$

Be that as it may, surely you just substitute the required values of x into the function and use a calculator to get the asnwer. How are you stuck in doing this?

3. It's actually like this,
$
f(x) = \frac{x}{\sqrt{x + 1-1}}
$

I have tried replacing the values with x but i keep getting the wrong answers..... i need to know the right way.

4. $

f(x) = \frac{x}{\sqrt{x + 1-1}}=\frac{x}{\sqrt{x}}=\sqrt{x}
$

Are you sure you've written it down correctly?

5. it's question 5 in the attached word document.

6. Originally Posted by ethio
it's question 5 in the attached word document.
The function is $f(x) = \frac{x}{\sqrt{x + 1} - 1}$.

7. yes, that's it, so what were the answers you got?

8. If the function is meant to be as was suggested in an earlier reply (and as you appear to have confirmed), then the listed "answer" values would seem to be incorrect.

9. ohh, ok.
well the method for evaluating this function maybe different or something, because when i worked them out i different values, that's what confused me.
anyway here is the answer sheet...........

10. I can't find that problem anywhere in your attachment. What number is it?

11. ## Thread closed.

This whole thread is turning into a shambles and is wasting time.

To the OP: Please re-post your question in a new thread - and make very sure you have posted the equation correctly and accurately. Ideally you will learn some basic latex to format your equation - go to this subforum: http://www.mathhelpforum.com/math-help/latex-help/