Consider the following function Find the inverse function of
Consider the following function. Find the inverse function of f.
Solution
f(x) = (x+1)/(x-3)
y = (x+1)/(x-3)
f(x) is not deifined for x=3 as denominator becomes zero
So, Domain (-inf , 3) U (3, inf)
Range : f(x) has horizontal asymtote at y=1
So, range (-inf, 1) U (1, inf)
f^-1(x) : plug x = y and y =x
x= (y+1)/(y -3)
xy -3x = y +1
y(x-1) = 1+3x
y = (1+3x)/(x-1)
f^-1(x) = (1+3x)/(x-1)
f^-1(x) does not exist for x=1 as den. becomes zero
So, Domain (-inf, 1) U (1, inf)
Range : f^-1(x) has horizontal asymtote at y =3
So, range (-inf , 3)U (3, inf)
