Notes 6-2

52
Section 6-2 Rational Power Functions

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Rational Power Functions

Transcript of Notes 6-2

Page 1: Notes 6-2

Section 6-2Rational Power Functions

Page 2: Notes 6-2

Warm-upThe frequencies of the notes beginning with A above

middle C are usually:

A = 440,A# = 440i21

12 ,B = 440i22

12 ,C = 440i23

12 ,

C # = 440i24

12 ,D = 440i25

12

1. Calculate the frequencies (to the nearest integer) of A#, B, C, C#, and D.

Page 3: Notes 6-2

Warm-upThe frequencies of the notes beginning with A above

middle C are usually:

A = 440,A# = 440i21

12 ,B = 440i22

12 ,C = 440i23

12 ,

C # = 440i24

12 ,D = 440i25

12

1. Calculate the frequencies (to the nearest integer) of A#, B, C, C#, and D.

466, 494, 523, 554, 587

Page 4: Notes 6-2

Warm-up2. Write an expression for the frequency of the note n

notes above A.

3. Use the expression you have written to find the frequency of the G that is two notes below A.

Page 5: Notes 6-2

Warm-up2. Write an expression for the frequency of the note n

notes above A.

440i2n

12

3. Use the expression you have written to find the frequency of the G that is two notes below A.

Page 6: Notes 6-2

Warm-up2. Write an expression for the frequency of the note n

notes above A.

440i2n

12

3. Use the expression you have written to find the frequency of the G that is two notes below A.

440i2−212

Page 7: Notes 6-2

Example 1Rewrite as a radical:

Page 8: Notes 6-2

Example 1Rewrite as a radical:

x47

Page 9: Notes 6-2

Example 1Rewrite as a radical:

x47

= x

17⎛

⎝⎞⎠

4

Page 10: Notes 6-2

Example 1Rewrite as a radical:

x47

= x

17⎛

⎝⎞⎠

4

= x7( )4

Page 11: Notes 6-2

Example 1Rewrite as a radical:

x47

= x

17⎛

⎝⎞⎠

4

= x7( )4

or

Page 12: Notes 6-2

Example 1Rewrite as a radical:

x47

= x

17⎛

⎝⎞⎠

4

= x4( )

17

= x7( )4

or

Page 13: Notes 6-2

Example 1Rewrite as a radical:

x47

= x

17⎛

⎝⎞⎠

4

= x4( )

17

= x7( )4

or

= x47

Page 14: Notes 6-2

Rational Exponent Theorem

Page 15: Notes 6-2

Rational Exponent Theorem

x

mn = x

1n⎛

⎝⎞⎠

m

= xn( )m

Page 16: Notes 6-2

Rational Exponent Theorem

x

mn = x

1n⎛

⎝⎞⎠

m

= xn( )mthe mth power of the positive nth root of x

Page 17: Notes 6-2

Rational Exponent Theorem

x

mn = x

1n⎛

⎝⎞⎠

m

= xn( )mthe mth power of the positive nth root of x

x

mn = xm( )

1n = xmn

Page 18: Notes 6-2

Rational Exponent Theorem

x

mn = x

1n⎛

⎝⎞⎠

m

= xn( )mthe mth power of the positive nth root of x

x

mn = xm( )

1n = xmn

the positive nth root of the mth power of x

Page 19: Notes 6-2

Postulates for Powers

Page 20: Notes 6-2

Postulates for Powers

xmixn = xm+n

Page 21: Notes 6-2

Postulates for Powers

xy( )m = xmym

xmixn = xm+n

Page 22: Notes 6-2

Postulates for Powers

xy( )m = xmym

xm

xn= xm−n ,x ≠ 0

xmixn = xm+n

Page 23: Notes 6-2

Postulates for Powers

xy( )m = xmym

xm

xn= xm−n ,x ≠ 0

xmixn = xm+n

xy( )m = xm

ym

Page 24: Notes 6-2

A couple others...

Page 25: Notes 6-2

A couple others...

x0 =1

Page 26: Notes 6-2

A couple others...

x0 =1

x−n = 1

xn

Page 27: Notes 6-2

Example 2Evaluate:

6423

Page 28: Notes 6-2

Example 2Evaluate:

6423

By hand:

Page 29: Notes 6-2

Example 2Evaluate:

6423

By hand:

64

13⎛

⎝⎞⎠

2

Page 30: Notes 6-2

Example 2Evaluate:

6423

By hand:

64

13⎛

⎝⎞⎠

2

= 42

Page 31: Notes 6-2

Example 2Evaluate:

6423

By hand:

64

13⎛

⎝⎞⎠

2

= 42 =16

Page 32: Notes 6-2

Example 2Evaluate:

6423

By hand:

64

13⎛

⎝⎞⎠

2

By Calculator:

= 42 =16

Page 33: Notes 6-2

Example 2Evaluate:

6423

By hand:

64

13⎛

⎝⎞⎠

2

By Calculator:

= 42 =16

Page 34: Notes 6-2

Example 3Evaluate:

32−35

Page 35: Notes 6-2

Example 3Evaluate:

32−35

By hand:

Page 36: Notes 6-2

Example 3Evaluate:

32−35

By hand:

32

15⎛

⎝⎞⎠

3⎛

⎝⎜

⎠⎟

−1

Page 37: Notes 6-2

Example 3Evaluate:

32−35

By hand:

32

15⎛

⎝⎞⎠

3⎛

⎝⎜

⎠⎟

−1

= 23( )−1

Page 38: Notes 6-2

Example 3Evaluate:

32−35

By hand:

32

15⎛

⎝⎞⎠

3⎛

⎝⎜

⎠⎟

−1

= 23( )−1

= 8−1

Page 39: Notes 6-2

Example 3Evaluate:

32−35

By hand:

32

15⎛

⎝⎞⎠

3⎛

⎝⎜

⎠⎟

−1

= 23( )−1

= 8−1

=18

Page 40: Notes 6-2

Example 3Evaluate:

32−35

By hand:

32

15⎛

⎝⎞⎠

3⎛

⎝⎜

⎠⎟

−1

= 23( )−1

= 8−1

=18

By calculator:

Page 41: Notes 6-2

Example 3Evaluate:

32−35

By hand:

32

15⎛

⎝⎞⎠

3⎛

⎝⎜

⎠⎟

−1

= 23( )−1

= 8−1

=18

By calculator:

Page 42: Notes 6-2

Example 4

y = h x( ) = x

32

a. Find an equation for the inverse of h.

Page 43: Notes 6-2

Example 4

y = h x( ) = x

32

a. Find an equation for the inverse of h.

y = x23

Page 44: Notes 6-2

Example 4

y = h x( ) = x

32

a. Find an equation for the inverse of h.

y = x23

b. Is the inverse a function?

Page 45: Notes 6-2

Example 4

y = h x( ) = x

32

a. Find an equation for the inverse of h.

y = x23

b. Is the inverse a function?Yes

Page 46: Notes 6-2

Example 4

y = h x( ) = x

32

a. Find an equation for the inverse of h.

y = x23

b. Is the inverse a function?Yes

...but only on D = {x: x ≥ 0}

Page 47: Notes 6-2

Example 4

y = h x( ) = x

32

a. Find an equation for the inverse of h.

y = x23

b. Is the inverse a function?Yes

...but only on D = {x: x ≥ 0}c. Plot h and its inverse

Page 48: Notes 6-2

Example 4

y = h x( ) = x

32

a. Find an equation for the inverse of h.

y = x23

b. Is the inverse a function?Yes

...but only on D = {x: x ≥ 0}c. Plot h and its inverse

Page 49: Notes 6-2

Example 4

y = h x( ) = x

32

a. Find an equation for the inverse of h.

y = x23

b. Is the inverse a function?Yes

...but only on D = {x: x ≥ 0}c. Plot h and its inverse

Page 50: Notes 6-2

Example 4

y = h x( ) = x

32

a. Find an equation for the inverse of h.

y = x23

b. Is the inverse a function?Yes

...but only on D = {x: x ≥ 0}c. Plot h and its inverse

Page 51: Notes 6-2

Homework

Page 52: Notes 6-2

Homework

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