Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley...

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Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2

Transcript of Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley...

Page 1: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Section 2.6Tangents, Velocities and Other Rates of Change

AP CalculusSeptember 18, 2009Berkley High School, D2B2

Page 2: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 2

Slope of the tangent line

Definition 1: The tangent line to the curve y=f(x) at the point P(a,f(a)) is the line through P with the slope…

ax

afxfm

ax

)()(lim

Page 3: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 3

Page 4: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 4

Example

Find an equation of the tangent line to the parabola y=x2 at the point P(1,1)

2

11

)1(lim1

)1)(1(lim

1

1lim

1

)1()(lim

)()(lim

:1 Def Using

1

1

22

1

1

xx

xxx

x

x

fxfax

afxfm

x

x

x

x

ax

Page 5: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 5

Example

Find an equation of the tangent line to the parabola y=x2 at the point P(1,1)

12

1

21

121

b. find toneedbut ,2

xy

b

b

b

bmxy

m

Page 6: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 6

Slope of the tangent line

Definition 2: The tangent line to the curve y=f(x) at the point P(a,f(a)) is the line through P with the slope…

h

afhafm

h

)()(lim

0

Page 7: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 7

Page 8: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 8

Example

Find an equation of the tangent line to the hyperbola y=3/x at the point P(3,1).

3

1

03

1

3

1lim

1

3lim

1

3

)3(3lim

33

33

lim

13

3

lim

)3()3(lim

)()(lim

:2 Def Using

0

0

0

0

0

0

0

h

hh

hhh

hh

hh

h

hh

h

fhfh

afhafm

h

h

h

h

h

h

h

Page 9: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 9

23

1

2

11

33

11

b. find toneedbut ,3

1

xy

b

b

b

bmxy

m

Example

Find an equation of the tangent line to the hyperbola y=3/x at the point P(3,1).

Page 10: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 10

Velocity

As we discussed earlier, if the equation describes position, then the slope represents velocity.

The secant line (between two points on the curve) represents average velocity.

The tangent line represent instantaneous velocity.

Page 11: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 11

Velocity

The tangent line represent instanteous velocity.

h

afhafav

h

)()(lim)(

0

Page 12: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 12

In general…

The secant line (between two points on the curve) represents average rate of change.

The tangent line represent instantaneous rate of change.

Look at what they are asking for in the problems, and use the appropriate definition.

Page 13: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 13

Assignment

Section 2.6, 1-17, odd (exclude 5)

Page 14: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 14

Page 15: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 15

Page 16: Section 2.6 Tangents, Velocities and Other Rates of Change AP Calculus September 18, 2009 Berkley High School, D2B2.

Calculus, Section 2.6 16

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Calculus, Section 2.6 17