Introduction to Mat 146

(Calculus II)

- Goals & Motivation

- How the course is organized & expectations

- Brief recall of Calculus I

- Student background information & feed-back

“LearningCalculus”

My Goals:

1) Help you acquire math knowledge (what for? …)

2) Help you develop your learning skills (what for? …)

Your Objectives:

- … and a good grade!

Resources for Calc II

  • Instructor: Lucian Ionescu

(Office hours, , Mat146 Web site)

  • Text: Thomas’ Calculus 11EE

Content:

6.Applications of integration

7. Log, exp & applications

8.Techniques of integration

9Differential equations (more gen. Int.)

10Infinite sequences and series (extend poly)

  • Calculator with a Computer Algebra System (CAS): TI-89/92 (Symbolic differentiation, integration, solving D.E., …)
  • Syllabus

1) Lecture – recitation format

2) Learning cycle

3) List of homework assignments – due W

4) Outlines, participation, attendence

5) Evaluation / grading scale

“Calculus: 1,2,3…”

Solving a Problem:

- Find the quantities involved-> variables;

- Find the relations among variables-> equations;

- Translate the questions into tasks (solving eq.);

- Apply the appropriate method;

- Interpret the result.

The Learning Cycle

  • What is “learning”? Acquisition of

- Knowledge

- Learning skills

  • How “to learn”? (Repetition is the key)

1. BEFORE class, skim through the assigned section (1/2 hour)

(Identify “keywords”).

2. Come to class and:

- Answer questions from the previous section (review);

- Ask questions from the current section;

- Take class notes; do not just “follow the explanations”;

- Focus on concepts and methods.

3. After class, review the material, and write an OUTLINE

(Concepts & steps of procedures);

4. Attempt all the homework problems (C):

a) First, without the help of the book;

b) If it doesn’t work, use the book (go back to 2. above);

c) Write a list of questions to ask (group/instructor).

  • Impact on grade: 1-4 leads to A!

Solving a Problem:

Thinking and Computing

I) High level mathematical language: “Modeling the real system”

- Concepts and relations: derivative, integral, etc. & theorems;

- Models: logistic model, etc.

- Methods to solve the models (“algorithms”): D.E., etc.

II) Mathematical code:

- Formulas and algebraic manipulations (rules to differentiate)

- Computations (evaluate a function, etc.)

- Executing the algorithms (solving a quadratic eq.)

Human’s job: (I)

Computer’s task: (II)

Your Concern (Task):

Translate a PROBLEM (I) into computer’s task (II).

Conclusions: what to learn?

- “The Theory”:

- Concepts and relations;

- Methods and Procedures

- How to “setup equations” (tasks for the computer)

- How to use the calculator

- How to interpret the results.

Example: “Volume by slicing”

(What to learn?)

- How to understand “Volume” (the concept):

1) Intuitively (Other sciences, own experience etc.)

2) Mathematically (measure, # of cubes -> )

- How to compute “Volume” (the math procedure):

- Input: type of data (description of the solid),

- Output: volume (positive number w. meaning!),

- Algorithm: adapting the input to the appropriate formula & performing the integration using the calculator (or by hand, to develop strong computational abilities).

Calculus I Recall

- Derivative & rate of change;

- Anti-derivatives = indefinite integral

- Integral & total change

- Riemann integral = definite integral

- FTC

- Part I: existence of antiderivatives;

- Part II: computing definite integrals.

- Interpretation: differentiation and integration are operations inverse to one another

Definite or Indefinite Integral

(What’s the difference anyway?)

I) Definite integral provides an antiderivative

(“Definite => indefinite”)

II) Antiderivatives allow to compute definite integrals

(“Indefinite => definite”)

Math 146 – Feedback no.1Name:______

1. If f(x)=x e3x, compute f ’(x)=

2. Find the local linearization of f(x)=arctan(x) at x=1.

3) Find the indefinite integral of x3.

4) When did you take Calc I?

5) What are YOUR goals in Calc II?

- Comments and suggestions:

- I wish …

Ch. 6 Applications of definite integrals

Recall:

- Riemann sums and integration = “Total change”

- FTC and total change from rate of change.

6.1 Volume by slicing

(ppt slides & examples)

Summary

- procedure “volume by slicing”

- input= description of the solid,

- output=volume

- idea: dimensional reduction with Cartesian coordinates

- algorithm / formula = integral of cross-section area (plane regions)

- Cavalieri’s principle (consequence)

- Solids of revolution (special description of solid => special cross-section):

1) disk method (cross-sections = disks)

2) washer method (c-s = washers)

- Examples / more practice

6.2 Volumes by cylindrical shells

- Same as “Volume by slicing”, except using polar coordinates for solids of revolution

Summary

- procedure: “volume by slicing”, input: description of the solid, output: volume

- idea: dimensional reduction with polar coordinates

- Cross-sections by constant coordinate surfaces: infinite cylinders

- algorithm / formula = integral of cross-section area (cylinders)

- Review & questions, discuss homework

- New material: keywords, ppt presentation (lecture), summary

- Peer concept check

6.3 Lengths of plane curves

- Idea: approximate + Pythagora+limit

- Parametric curves

- Justifying the formula: Pythagora => length formula

- Example: input, formula / TI-89 => output

- Graph of a function:

- Justification: special case of parameterization x=t, y=f(x)=f(t)

- Example

- Differential formula: L= ds, ds=(dx2+dy2)½

- Summary: s, ds, parameterization, graph (special parameterization)

6.4 Moments and the Center of Mass

- Center of Mass

- Torque of a mass: mgx; moment: mx

- Main property of CM: equilibrium = cancellation of torques / moments

- Formula;

- Interpretation: coordinate of CM = average coordinates (with weights)

- 1dim objects: Wires and Thin rods

- 2dim objects: Thin flat plate (1-integrals)

- Examples – practice

6.5 Areas of surfaces of revolution and the Theorem of Pappus

- Surface area

- Dimensional reduction with Cartesian coordinates

- Surface of revolution: cross-sections=circles

- “Same (type) of formula”: the differential form  L(x)ds,

- Cross-section circumference: L(x)=2 r(x)

- Differential arc length:

1) graph: ds=(1+f’2)½ ,

2) parameterized curve ds2=dx2+dy2

- Theorem of Pappus

1) Volume of Solid of revolution: A(cross-section) x L(Centre of Mass Circle)

justification: Average circumference=CM Circle

2) Area of Surface of Revolution= L(cross-section) x L(Centre of Mass Circle)

justification: same, 1-dimension lower.

6.6 Work

Work

- Work done by a constant force

- Work done by a variable force in 1-dimension

Examples

- Elastic force & Hooks law for Springs (F=-kx)

- Gravity & Pumping liquids from containers (F=mg)

6.7 Fluid Pressures and Forces

Pressure

- Pressure = Force / unit of surface; scalar: same in all directions at a point

- The Pressure-Depth Equation: p=wh

Force

- Constant-depth formula for the fluid force: F=pA

- Variable-depth formula: F=p dA, vertical plate: dA=width x dh

- Fluid forces and centroids: F=w hc A

Ch. 7 Integrals and Transcendental Funcations

- A precise introduction of exp, ln and hyperbolic functions (analog of cos & sin)

7.1 The Logarithm define as an Integral

The natural logarithm function

- Def. ln x=1/t dt, a few values

- Number e

- The derivative of ln x and of ln|x|

- Graph and range of ln x

- Properties of ln with proofs

- The integral of ln u (u<0 and u>0)

- Example 1

The inverse of ln(x):

- The natural exponential

- The derivative, integral, example 2 (IVP)

- Properties: laws of exponents

General exponential function

- Def. a^x, log_a(x), derivatives and integral

- Properties

- Example 3

7.2 Exponential Growth and Decay

The law of exponential change

- Def.

- The DE model

Applications

- Unlimited population growth

- Continuous compounded interest: k times/year and continuous limit

- Radioactivity

- Heat transfer and Newton’s Law of Cooling

7.3 Relative rates of growth

- Which functions grow faster? Poly, exp, log …

- Comparing growth rates:

1) Asymptotically (“at infinity”)

2) At a point: rates of change and relative rates of change

1) Order of magnitude: lim f(x)/g(x)= finite, 0, infinite

- Grows at the “same rate”, “slower than”, “faster than”

2) Rates if change of functions at a point:

- Absolute: y’(a);

- Relative: y’(a)/y(a);

- Example: Population growth, bank account amount

7.4 Hyperbolic functions

- Abstract: analogs of trigonometric functions

- Even and odd parts of the exponential

- Def. hyperbolic functions sinh, cosh,

- Main identity, geometric interpretation: circle & (equilateral) hyperbola

- Derivatives and integrals

- Derived hyperbolic functions: tanh, coth, sech, csch etc.

- Inverse hyperbolic functions: def., derivatives and integrals (use calculator);

Ch. 8 Techniques of Integration

- Recall FTC

8.1 Basic Integration Formulas

- Substitution rule

- Examples

8.2 Integration by parts

- Product rule in integral form

- Integration by parts formula

- Evaluating definite integrals by parts

8.3 Integration of rational functions by partial fractions

- Example of a decomposition

- General description of the Method

- Reduction of degree of numerator

- Examples

- Heaviside cover-up method for linear factors – Example 6

8.4 Trigonometric integrals

- Products of powers of sines and cosines

- Eliminating square roots

- Integrals of powers of tan x and sec x

- Products of sines and cosines (Example 7)

8.5 Trigonometric substitutions

- Three basic substitutions

- Examples

8.6 Integral Tables and Computer Algebra Systems

- Integral tables

- Reduction formulas

- Non-elementary integrals

- Integration with a CAS

8.7 Numerical Integration

- Trapezoidal approximations – the trapezoidal rule

- Error estimate for the trapezoidal rule

- Simpson’s rule: approximating using parabolas

- Error estimate for Simpson’s rule

8.8 Improper integrals

- Infinite limits of integration

- Integrands with vertical asymptotes

- Tests for convergence and divergence

- Direct comparison test

- Limit comparison test

Ch. 9 Further applications of integration

- From integral (definite/indefinite) to more general DE

9.1 Slope fields and separable differential equations

- General 1st ODE

- Slope fields: viewing solution curves – use calculator

- Separate equations

- Torricelli’s law – Ex.5

9.2 First-order linear DE

- The growth/decay equation, having a linear form

- Standard form, Ex.1

- Solving linear equations

- RL Circuits

- Mixture problems

9.3 Euler’s Method

- Euler’ method

- Improved Euler’s method

9.4 Graphical solutions of autonomous DE

- Equilibrium values and phase lines

- Stable and unstable equilibria

- Population growth in a limited environment

9.5 Applications of 1st ODE

- Resistance proportional to velocity

- Modeling population growth

- relative growth rate

- carrying capacity

- Orthogonal trajectories

Ch. 11 Infinite sequences and series

11.1 Sequences

- Infinite sequences

- Convergence and divergence

- Diverges to infinity

- Calculating limits of sequences

- The sandwitch theorem for sequences

- Using l’Hospital Rule

- Commonly occurring limits

- Recursive definitions

- Bounded non-decreasing sequences

- The non-decreasing Theorem

11.2 Infinite series

- Geometric series

- Divergent series

- The nth-term test for divergence

- Combining series

- Adding or deleting terms

- Reindexing

11.3 The integral test

- Non-decreasing partial sums

- The integral test

11.4 Comparison tests

- The comparison test

- The limit comparison test

11.5 The ratio and root test

- The ratio test, - The root test

11.6 Alternating series, absolute and conditional convergence

- Alternating series, harmonic series

- The Alternating Series Estimation Theorem

- Absolute and conditional convergence

- Absolute convergent

- Conditionally convergent

- The absolute convergence test

- Rearranging series

11.7 Power series

- Power series and convergence

- The convergence theorem for power series

- The radius of convergence of a power series

- Term-by-term differentiation

- Term-by-term differentiation theorem

- Term-by-term integration theorem

- Multiplication of power series

11.8 Taylor and MacLaurin series

- Series representations

- Taylor and MacLaurin Series

- Taylor polynomials

- Taylor polynomial of order n

11.9 Convergence of Taylor Series; error estimates

- Taylor Theorem / Taylor’s formula

- Estimating the remainder

- Truncation error

- Combining Taylor series

- Euler’s identity

11.10 Applications of power series

- The binomial series for powers and roots

- Power series solutions of DE

- Evaluating nonelementary integrals

- Arctangents

- Evaluating indeterminate forms

11.11 Fourier Series

- Fourier series, finding coefficients

- Convergence of Fourier Series