# Thread: function- f(x) and g(x)

1. ## function- f(x) and g(x)

Let f(x)= 3√x+2 and g(x)= x^3-2
Which of the following are true?

a. g(x)=f^-1(x) for all real values of x
b. (f o g)(x)=1 for all real values of x
c. The function f is one-to-one.

I think the answer is only c is true. Am I correct?

Thanks!

2. Is that $3\sqrt{x}+2$ or $3\sqrt{x+2}$?

3. the second one you wrote...but the 3 is tiny, like inside ?? the outside of the symbol,,if you know what I mean?

4. Originally Posted by live_laugh_luv27
the second one you wrote...but the 3 is tiny, like inside ?? the outside of the symbol,,if you know what I mean?
$y = \sqrt[3]{x+2}$

5. yes! thanks

6. Originally Posted by live_laugh_luv27
yes! thanks
Can you choose more than one answer - well hell you must to be honest. But does it say to choose more than one answer?

7. Yes you can choose more than one..any combination

8. For choice (b),
$(f \circ g)(x) = \sqrt[3]{(x^3 - 2) + 2}$
is this going to equal 1?

01

9. Originally Posted by yeongil
For choice (b),
$(f \circ g)(x) = \sqrt[3]{(x^3 - 2) + 2}$
is this going to equal 1?

01
Yes...but does that mean it will equal 1 for all real numbers? Like, if you plugged a 2 in instead?

10. Originally Posted by live_laugh_luv27
Yes...but does that mean it will equal 1 for all real numbers? Like, if you plugged a 2 in instead?
try x = 2 ... does it give you a value equal to 1?

11. Originally Posted by skeeter
try x = 2 ... does it give you a value equal to 1?
No, I didn't..did I do something wrong?

12. Originally Posted by live_laugh_luv27
No, I didn't..did I do something wrong?
what's that tell you about statement (b), then?

13. Originally Posted by skeeter
what's that tell you about statement (b), then?
it is not correct.

14. Originally Posted by live_laugh_luv27
it is not correct.
Bingo!

15. Originally Posted by skeeter
Bingo!
ok, but I am still unsure about choice a.

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