# Thread: The inverse of function

1. ## The inverse of function

Hi Guys ,,
What the inverse of function means ? Like if i have the following function : 2-6x , What is it's inverse ?

Thank you

2. Originally Posted by metallica007
Hi Guys ,,
What the inverse of function means ? Like if i have the following function : 2-6x , What is it's inverse ?

Thank you
if a function has a rule $\displaystyle f(x) = y$ , then its inverse is $\displaystyle f(y) = x$

so, if $\displaystyle y = 2-6x$ , then its inverse is $\displaystyle x = \frac{2-y}{6}$

see here for more detailed information ...

Inverse Functions: Definition / Drawing Inverses

3. so the inverse of $\displaystyle f(x)=2-6x$
put $\displaystyle f(x)=y.$
$\displaystyle y=2-6x.$
flip y and x
$\displaystyle x=2-6y.$
solve for y.
$\displaystyle y=\frac{2-x}{6}$
change y by $\displaystyle f^{-1}(x)$
$\displaystyle f^{-1}(x)=\frac{2-x}{6}$ and that's your inverse.

4. look at the graph of both the function and it's inverse.
(the inverse is the blue line)
(enjoy the symmetry)

5. Thanks guys :-)