Please help and explain!!!!!! I will fan and give medals!

If f(x)= 3/(x+1), which equations represents the inverse of function f(x)?

f^-1(x)= -3/(x+1)
f^-1(x)= 3/(x-1)
f^-1(x)= (x+1)/3
f^-1(x)= 3x/(1+x)

Question

Please help and explain!!!!!! I will fan and give medals!

If f(x)= 3/(x+1), which equations represents the inverse of function f(x)?

f^-1(x)= -3/(x+1)
f^-1(x)= 3/(x-1)
f^-1(x)= (x+1)/3
f^-1(x)= 3x/(1+x)

anonymous · Answer

oh no!

anonymous · Answer

you are looking for the inverse function

anonymous · Answer

$$f(x)=\frac{3}{x+1}$$ and you want $f^{-1}(x)$  the inverse
start by setting 
$$y=\frac{3}{x+1}$$ then switch $x$ and $y$ to get 
$$x=\frac{3}{y+1}$$ and solve the equation for $y$

anonymous · Answer

this takes a couple steps, do you know how to do it?

anonymous · Answer

I think so. Is the correct answer |dw:1368557976174:dw|

anonymous · Answer

i don't think so
lets solve it

anonymous · Answer

damn typo
$$x=\frac{3}{y+1}$$
$$x(y+1)=3$$
$$xy+x=3$$
$$xy=3-x$$
$$y=\frac{3-x}{x}$$

anonymous · Answer

so answer is 
$$f^{-1}(x)=\frac{3-x}{x}$$

anonymous · Answer

Thank you so much! Now I know for sure how to solve problems like this. You helped tremendously!

anonymous · Answer

yw
i notice however that this is not one of your answer choices
i am sure that it is right, but i am confused as to why this doesn't appear in your list