College Algebra & Trigonometry I - 2.7 - Inverse ... - Hicham Qasmi

f(x) = 3x + 2 and g(x) = x − 2. 3. Math 1100. College Algebra & Trigonometry I ... If f has an inverse function, replace y in step 3 by f−1(x). −→ So, f−1(x) = x ..... √x − 1. Since y is not uniquely defined by x, There is no inverse! Math 1100. College ...
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Outline Inverse Functions One-to-One Functions

College Algebra & Trigonometry I 2.7 - Inverse Functions Math 1100 North Carolina Central University Math & C.S. Department Hicham Qasmi - [email protected]

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

1

Inverse Functions Definition Example Find Function Inverses

2

One-to-One Functions Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

1

Inverse Functions Definition Example Find Function Inverses

2

One-to-One Functions Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Outline

1

Inverse Functions Definition Example Find Function Inverses

2

One-to-One Functions Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Inverse Functions Theorem Let f and g be 2 functions so that  f g(x) = x for every x in the domain of g and  g f (x) = x for every x in the domain of f The function g is called the inverse of f and is denoted by f −1 . Thus,   f f −1 (x) = x and f −1 f (x) = x The domain of f −1 is the range of f The range of f −1 is the domain of f .

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Inverse Functions Theorem Let f and g be 2 functions so that  f g(x) = x for every x in the domain of g and  g f (x) = x for every x in the domain of f The function g is called the inverse of f and is denoted by f −1 . Thus,   f f −1 (x) = x and f −1 f (x) = x The domain of f −1 is the range of f The range of f −1 is the domain of f .

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Inverse Functions Theorem Let f and g be 2 functions so that  f g(x) = x for every x in the domain of g and  g f (x) = x for every x in the domain of f The function g is called the inverse of f and is denoted by f −1 . Thus,   f f −1 (x) = x and f −1 f (x) = x The domain of f −1 is the range of f The range of f −1 is the domain of f .

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Inverse Functions Theorem Let f and g be 2 functions so that  f g(x) = x for every x in the domain of g and  g f (x) = x for every x in the domain of f The function g is called the inverse of f and is denoted by f −1 . Thus,   f f −1 (x) = x and f −1 f (x) = x The domain of f −1 is the range of f The range of f −1 is the domain of f .

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Inverse Functions Theorem Let f and g be 2 functions so that  f g(x) = x for every x in the domain of g and  g f (x) = x for every x in the domain of f The function g is called the inverse of f and is denoted by f −1 . Thus,   f f −1 (x) = x and f −1 f (x) = x The domain of f −1 is the range of f The range of f −1 is the domain of f .

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Inverse Functions Theorem Let f and g be 2 functions so that  f g(x) = x for every x in the domain of g and  g f (x) = x for every x in the domain of f The function g is called the inverse of f and is denoted by f −1 . Thus,   f f −1 (x) = x and f −1 f (x) = x The domain of f −1 is the range of f The range of f −1 is the domain of f .

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Outline

1

Inverse Functions Definition Example Find Function Inverses

2

One-to-One Functions Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Example of the Inverse of a Functions

Example Show that each function is the inverse of the other: f (x) = 3x + 2 and g(x) =

Math 1100

x −2 3

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Outline

1

Inverse Functions Definition Example Find Function Inverses

2

One-to-One Functions Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Find the Inverse of a Function 1

Replace f (x) in the equation with y −→ for f (x) = x + 2, it means y = x + 2

2

Interchange x and y in the equation y = f (x) −→ x = y + 2

3

Solve for y −→ y = x − 2

4

If the equation does not define y as a function of x, then the function does not have an inverse. If it does, then f has an inverse function −→ This defines y as a function of x, so f −1 exists

5

If f has an inverse function, replace y in step 3 by f −1 (x) −→ So, f −1 (x) = x − 2   Verify f f −1 (x) = x and f −1 f (x) = x.  −→ f f −1 (x) = (x − 2) + 2 = x  −→ f −1 f (x) = (x + 2) − 2 = x

6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Definition Example Find Function Inverses

Example Find the inverse of: 1 2 3

f (x) = 7x − 2

g(x) = x 3 + 1 f (x) =

5 x

+4

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Outline

1

Inverse Functions Definition Example Find Function Inverses

2

One-to-One Functions Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Function Without Inverse

Example Try to find the inverse of f (x) = x 2 + 1: f (x) = x 2 + 1 y = x2 + 1 x = y2 + 1 y2 = x √ −1 y =± x −1 Since y is not uniquely defined by x, There is no inverse!

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Function Without Inverse

Example Try to find the inverse of f (x) = x 2 + 1: f (x) = x 2 + 1 y = x2 + 1 x = y2 + 1 y2 = x √ −1 y =± x −1 Since y is not uniquely defined by x, There is no inverse!

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Function Without Inverse

Example Try to find the inverse of f (x) = x 2 + 1: f (x) = x 2 + 1 y = x2 + 1 x = y2 + 1 y2 = x √ −1 y =± x −1 Since y is not uniquely defined by x, There is no inverse!

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Function Without Inverse

Example Try to find the inverse of f (x) = x 2 + 1: f (x) = x 2 + 1 y = x2 + 1 x = y2 + 1 y2 = x √ −1 y =± x −1 Since y is not uniquely defined by x, There is no inverse!

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Function Without Inverse

Example Try to find the inverse of f (x) = x 2 + 1: f (x) = x 2 + 1 y = x2 + 1 x = y2 + 1 y2 = x √ −1 y =± x −1 Since y is not uniquely defined by x, There is no inverse!

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Function Without Inverse

Example Try to find the inverse of f (x) = x 2 + 1: f (x) = x 2 + 1 y = x2 + 1 x = y2 + 1 y2 = x √ −1 y =± x −1 Since y is not uniquely defined by x, There is no inverse!

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Outline

1

Inverse Functions Definition Example Find Function Inverses

2

One-to-One Functions Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Horizontal Line Test

Theorem A function f has an inverse if there is no horizontal line that intersects the graph of y = f (x) at more than one point.

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Which of these functions have inverse functions?

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Which of these functions have inverse functions?

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Which of these functions have inverse functions?

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Which of these functions have inverse functions?

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Outline

1

Inverse Functions Definition Example Find Function Inverses

2

One-to-One Functions Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

One-to-One Function Theorem A function f is a one-to-one function if for any x1 and x2 f (x1 ) = f (x2 )

means x1 = x2

(A One-to-One Function is also called an injection) In other words, no 2 different ordered pairs have the same second y-coordinate. A One-to-One function always verifiy the Horizontal line test Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

One-to-One Function Theorem A function f is a one-to-one function if for any x1 and x2 f (x1 ) = f (x2 )

means x1 = x2

(A One-to-One Function is also called an injection) In other words, no 2 different ordered pairs have the same second y-coordinate. A One-to-One function always verifiy the Horizontal line test Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

One-to-One Function Theorem A function f is a one-to-one function if for any x1 and x2 f (x1 ) = f (x2 )

means x1 = x2

(A One-to-One Function is also called an injection) In other words, no 2 different ordered pairs have the same second y-coordinate. A One-to-One function always verifiy the Horizontal line test Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Outline

1

Inverse Functions Definition Example Find Function Inverses

2

One-to-One Functions Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Graphing the inverse of a Function

Property The graph of f −1 is a reflection of the graph of f about the line y = x (1st quadrant bisector)

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Graphing the inverse of a Function

Property The graph of f −1 is a reflection of the graph of f about the line y = x (1st quadrant bisector)

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Graph of f deduced from the Graph of f −1

6 5 4 3 2 1 0

y = f (x)

0 1 2 3 4 5 6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Graph of f deduced from the Graph of f −1

6 5 4 3 2 1 0

y = f (x) (a, b)•

0 1 2 3 4 5 6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Graph of f deduced from the Graph of f −1

6 5 4 3 2 1 0

y = f (x) y =x (a, b)•

reflection

0 1 2 3 4 5 6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Graph of f deduced from the Graph of f −1

6 5 4 3 2 1 0

y = f (x) y =x (a, b)•

reflection (b, a) •

0 1 2 3 4 5 6

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Graph of f deduced from the Graph of f −1

6 5 4 3 2 1 0

y = f (x) y =x (a, b)•

reflection (b, a) •

y = f −1 (x)

0 1 2 3 4 5 6

Math 1100

College Algebra & Trigonometry I

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Outline Inverse Functions One-to-One Functions

Example of Graph of f −1 Use the graph of f below to draw the graph of f −1 5 4 3

(4, 2)

2



y = f (x)

1

(−1, 0)

0 −5 −4 −3 −2 −1 0 −1 •

1

2

3

4

5

(−3, −2) •

−2 −3 −4 −5

Math 1100

College Algebra & Trigonometry I

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Outline Inverse Functions One-to-One Functions

Example of Graph of f −1 Use the graph of f below to draw the graph of f −1 5 4

(2, 4) •

3

(4, 2)

2



y = f (x)

1

(−1, 0)

0 −5 −4 −3 −2 −1 0 1 2 • 0) −1(−1, •

3

4

5

(−3, −2) •

−2 •

−3

(−2, −3)

−4 −5

Math 1100

College Algebra & Trigonometry I

Outline Inverse Functions One-to-One Functions

Function Without Inverse Horizontal Line Test Definition Graph of f and f −1

Example of Graph of f −1

1

2

Find the inverse of f (x) = x 2 − 1 when the domain of f is limited to the positive numbers. For x ≤ 0, graph f and f −1 in the same rectangular coordinate system.

Math 1100

College Algebra & Trigonometry I