x =2y/5 -y
5x = 2y -5y
5x = -3y
F(x) = -5x/3
Find the inverse of each of these functions
a)f(x)=x/x+2
b)f(x)=2x/5-x
c)f(x)=3x/2x+1
2 answers
1st one:
if f(x) = x/(x+2) , then y = x/(x+2)
step1: interchange the x and y variables to get the inverse as
x = y/(y+2)
step 2: solve this new equation for y
x = y/(y+2)
xy + 2x = y
xy - y = -2x
y(x-1) = -2x
y = -2x/(x-1) or y = 2x/(1-x)
f^-1 (x) = 2x/(1-x)
now do the same for others following these two steps.
if f(x) = x/(x+2) , then y = x/(x+2)
step1: interchange the x and y variables to get the inverse as
x = y/(y+2)
step 2: solve this new equation for y
x = y/(y+2)
xy + 2x = y
xy - y = -2x
y(x-1) = -2x
y = -2x/(x-1) or y = 2x/(1-x)
f^-1 (x) = 2x/(1-x)
now do the same for others following these two steps.