Question
If g(x)=3x-5, then g inverse(x)=
Answers
MathMate
Three steps to inverse:
1. interchange x and y
2. solve y in terms of x
3. evaluate f<sup>-1</sup>(f(x)) to make sure you get back x.
1. Interchange x and y
Let y=g(x)=3x-5
then
x=3y-5
2. solve for y
y=(x+5)/3
3. evaluate g<sup>-1</sup>(g(x))
g<sup>-1</sup>(g(x))
=([3x-5]+5)/3
=(3x)/3
=x OK
1. interchange x and y
2. solve y in terms of x
3. evaluate f<sup>-1</sup>(f(x)) to make sure you get back x.
1. Interchange x and y
Let y=g(x)=3x-5
then
x=3y-5
2. solve for y
y=(x+5)/3
3. evaluate g<sup>-1</sup>(g(x))
g<sup>-1</sup>(g(x))
=([3x-5]+5)/3
=(3x)/3
=x OK