Showing posts with label Inverse Function. Show all posts
Showing posts with label Inverse Function. Show all posts

Monday, March 16, 2009

Question on Finding the Value of Inverse Function

Topic : Inverse Function

Question : Find the inverse of the Function f(x)=(4x-1)/(3x+2)

Solution :
Let g be the inverse of function f then,
f(g(x)) = x So,
4g(x)-1
--------- = x
3g(x)+2
For convinience, lets write only g instead of g(x)
So 4g-1 / 3g+2 = x
4g-1=x(3g+2)
4g-1=3gx+2x
Subtract 3gx on both sides
4g-3gx-1 = 2x
add 1 from both sides
4g-3gx = 2x +1
g(4-3x) = 2x+1
g=2x+1 / (4-3x)
or g = - (2x+1) / (3x+4)
and inverse of f(x) is - (2x+1) / (3x+4)