3. nverse Function
Steps in Solving
Inverse Function
1. Write the function
in the form of y=f(x)
2. Interchange the x
and y variables.
3. Solve for y in terms
of x.
Ex. 1) F(x) = 3x + 1
y = 3x + 1
x = 3y + 1
x-1 3x
3 3
y =
x-1
3
=
4. Ex. 2) F(x) = x3 - 2
y = x 3 - 2
x = y 3 - 2
=
3 x + 2 3 y 3
3 x + 2
y =
Ex. 3) F(x) = 2x + 1
3x - 4
y = 2x + 1
3x - 4
x = 2y + 1
3y - 4
1
3xy – 4x = 2y + 1
3xy – 2y = 4x + 1
y ( 3x – 2 ) = 4x + 1
3x - 2 3x - 2
5. y ( 3x – 2 ) = 4x + 1
3x - 2 3x - 2
y = 4x +1
3x - 2
Ex. 4) F(x) = 5x - 2
Ex. 5) F(x) = x 2 + 1
y = x + 2
5
y = x - 1
et’s Try to Solve!
6. Let’s see if
veryone listened
Quiz
1. f(x) = 2x + 7
2. f(x) = x - 2
Good Luck !
3x + 5
Correct Answers
1. Y = x -7
2
2. Y = -5x -2
3x - 1
