the function f(x)=4/x+2 is one to one find an equation for f^-1(x) the inverse function f^-1(x) please help

Question

anonymous · Answer

You just need to use the definition of inverse function.  A function $$f^{-1}(x)$$is an inverse to the function $$f(x)$$if$$f(f^{-1}(x))=f^{-1}(f(x))=x$$So this is what you do.  For $$f(x)=\frac{4}{x}+2$$applying the definition,$$f(f^{-1}(x))=\frac{4}{f^{-1}(x)}+2=x$$So$$\frac{4}{f^{-1}(x)}=x-2\rightarrow f^{-1}(x)=\frac{4}{x-2}$$

anonymous · Answer

ima guess this is 
$$f(x)=\frac{4}{x+2}$$

myininaya · Answer

$$y=\frac{4}{x+2}$$
$$y(x+2)=4$$
$$xy+2y=4$$
$$xy=4-2y$$
$$x=\frac{4-2y}{y}$$
$$f^{-1}(x)=\frac{4}{x}-2$$

anonymous · Answer

myininaya help me here will you please?

anonymous · Answer

http://openstudy.com/groups/mathematics#/groups/mathematics/updates/4e029abf0b8bbe4f12e8b417