Calculus with Dr. Bob II: Basic Integration

Video Lectures

Displaying all 39 video lectures.
Lecture 1
Definition of Antiderivative
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Definition of Antiderivative
Calculus: We define an antiderivative of a function f and explain indefinite integration as a process that undoes differentiation. We show that all antiderivatives of a function may be obtained by finding a single antiderivative and adding constants. We emphasize checking work and note that correct answers may need more work due the constant of integration.
Lecture 2
Antiderivative of a Polynomial
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Antiderivative of a Polynomial
Calculus: We note rules for the antiderivative of a sum and scalar multiple. With these, we are able to find the indefinite integral of any polynomial. We also give an example with negative powers of x and a cruder method for checking our answer.
Lecture 3
Antiderivative of (x-1)(x-2)/sqrt(x^3)
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Antiderivative of (x-1)(x-2)/sqrt(x^3)
Worked problem in calculus. The antiderivative of (x-1)(x-2)/ sqrt(x^3) is calculated.
Lecture 4
Basic Trig Antiderivatives
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Basic Trig Antiderivatives
Calculus: We note the identity int F' dx = F(x) + C and apply it to the basic trig functions. As examples, we compute int [cos(.5x) -sin(.5x)]^2 dx and int cos(x)/(1 - cos^2(x)) dx.
Lecture 5
Antiderivative of tan^2(x)
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Antiderivative of tan^2(x)
Worked problem in calculus. The antiderivative of tan^2(x) is computed.
Lecture 6
Antiderivative of sin(x)/[1-sin^2(x)]
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Antiderivative of sin(x)/[1-sin^2(x)]
Worked problem in calculus. The antiderivative of sin(x)/[1-sin^2(x)] is calculated.
Lecture 7
Visualizing an Antiderivative
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Visualizing an Antiderivative
Calculus: We explain the connection from the graph of a function f to its antiderivatives F + C. We consider the special case of f(x) = 2x + 2 and draw an analogy to the point-slope description of a line.
Lecture 8
Graphing f(x) from f'(x)
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Graphing f(x) from f'(x)
Worked problem in calculus. The graph of the derivative f'(x) is given. We show how the graph of f(x) is obtained.
Lecture 9
Antiderivative of a Piecewise-Defined Function
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Antiderivative of a Piecewise-Defined Function
Calculus: Suppose f(x) is continuous on the real line, f(0) = 10, f(10) = 100, and f'(x) = x+1 on x lt 0, r on 0 lt x lt 20, and 5 on x gt 20. Find f(x) and compare its graph with f'(x).
Lecture 10
Solving Differential Equations
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Solving Differential Equations
Worked problem in calculus. We solve the differential equation f"(x) = x^{-1/2} + 1, f'(9) = 7, and f(4) = 32/3.
Lecture 11
Equations of Motion
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Equations of Motion
Worked problem in calculus. From a height of 50m, an object is tossed into the air. If the maximum height is 150m, what was the initial velocity?
Lecture 12
Overview of Rectangular Approximation of Area
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Overview of Rectangular Approximation of Area
Calculus: We describe a process for approximating the area under the graph of a positive function using rectangles. We apply this process to the special case of f(x) = 1 + x over the interval [1, 2] with 10 and n rectangles. As a final note, we define sigma notation, partitions, and Riemann sums.
Lecture 13
Rectangular Approximation of Area
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Rectangular Approximation of Area
Worked problem in calculus. The area under the graph f(x) = sqrt(4-x^2) over [0,2] is approximated using 6 rectangles (upper and lower).
Lecture 14
Overview of Summation Formulas
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Overview of Summation Formulas
Calculus: We review some basic summation formulas and rules for calculating Riemann sums. Over the range i from 1 to n, we state formulas for the sum of a constant r, i, i^2 and i^3. We review sigma notation and prove the rules for r, i and i^2. We also work out the special case of sum 1 to 4 of (i+1)^2 using our formulas.
Lecture 15
Limit Summation Formula
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Limit Summation Formula
Worked problem in calculus. We compute a closed formula for the summation over i (from 1 to n) of (1 + i/n)^2 (1/n). Then the limit is taken as n goes to infinity.
Lecture 16
General Method for Integer Power Sum Formula
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General Method for Integer Power Sum Formula
Calculus: We give a general method for deriving the closed formula for sums of powers of 1 through N. The technique uses the partial sum formula for geometric power series.
Lecture 17
Riemann Sum with Signed Area
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Riemann Sum with Signed Area
Calculus: Calculate the Riemann sum for the function f(x) = (x-1)^2-1 over the interval [1,3] with 10 rectangles and using right endpoint. The graph is below the x-axis on [1,2]. We also compute the Riemann sum for n rectangles and let n go to infinity.
Lecture 18
Limit Process for Area
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Limit Process for Area
Worked problem in calculus. The limit process for area is carried out for f(x) = 4x - x^3 over the interval [0,2].
Lecture 19
Definition of Definite Integral
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Definition of Definite Integral
Calculus: We review the process for finding the area under a curve and give a definition for a definite integral when f(x) is continuous over an interval [a,b]. We state basic rules for definite integrals. Examples include f(x) = x+2 over [-1, 1] and f(x) = -sqrt(4-x^2) over [-2,2].
Lecture 20
Definite Integral as Area 1 - Using the Graph
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Definite Integral as Area 1 - Using the Graph
Worked problem in Calculus. The definite integral int_0^2 sqrt(4x-x^2) dx is computed by graphing the curve and applying a geometric formula for the area.
Lecture 21
Definite Integral as Area 2 - Breaking Up the Region
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Definite Integral as Area 2 - Breaking Up the Region
Worked problem in calculus. Given the graph of f(x), we compute definite integrals of f(x) using geometric methods.
Lecture 22
Definite Integral as Area 3 - Area Below the x-axis
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Definite Integral as Area 3 - Area Below the x-axis
Worked problem in calculus. Find a and b such that the definite integral
int_a^b -6+5x-x^2 dx is maximized.
Lecture 23
The First Fundamental Theorem of Calculus
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The First Fundamental Theorem of Calculus
Calculus: We state and prove the First Fundamental Theorem of Calculus. Before the proof, we show the following examples: (a) constant function (rectangle), (b) line through origin (triangle), (c) f(x) = sin(x) over [0, pi], and (d) f(x) = (x-1)^2 -1 over [1,3]. The key step in the proof is to reinterpret the Mean Value Theorem. We also note the interpretation for motion in a line.
Lecture 24
Area Under a Curve 1
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Area Under a Curve 1
Worked problem in calculus. The area under the curve f(x) = |x^2 - 4x +3| over the interval [0, 4] is calculated using the First Fundamental Theorem of Calculus. The key step is break the interval into three regions.
Lecture 25
Area Under a Curve 2
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Area Under a Curve 2
Worked problem in calculus. We calculate the area bounded by the curve f(x) = x^3 - x and the x-axis using the First Fundamental Theorem of Calculus.
Lecture 26
The Mean Value Theorem for Integrals
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The Mean Value Theorem for Integrals
Calculus: We state and prove the Mean Value Theorem for Integrals. Examples include (a) f(x) = x+ 2 over the interval [1, 3], and (b) f(x) = x^5 - x over the interval [0, 1].
Lecture 27
Example of Mean Value Theorem for Integration
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Example of Mean Value Theorem for Integration
Worked problem in calculus. An example of the Mean Value Theorem is worked out for f(x) = sin(x) over the interval [0, pi/2].
Lecture 28
The Second Fundamental Theorem of Calculus
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The Second Fundamental Theorem of Calculus
Calculus: We state and prove the Second Fundamental Theorem of Calculus. A formula is given for an antiderivative of f(x) when continuous on [a,b]. We interpret the result in terms of the area function for f(x) and note some examples and applications.
Lecture 29
Example of 2nd Fundamental Theorem of Calculus 1
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Example of 2nd Fundamental Theorem of Calculus 1
Worked problem in calculus. The Second Fundamental Theorem of Calculus is used to graph the area function for f(x) when only the graph of f(x) is given.
Lecture 30
Example of 2nd Fundamental Theorem of Calculus 2
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Example of 2nd Fundamental Theorem of Calculus 2
Worked problem in calculus. The Second Fundamental Theorem of Calculus is combined with the chain rule to find the derivative of F(x) = int_{x^2}^{x^3} sin(t^2) dt.
Lecture 31
Integration By Substitution: Antiderivatives
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Integration By Substitution: Antiderivatives
Calculus: We introduce the technique of integration by substitution for indefinite integrals. This is an integration method that reverses the chain rule for derivatives.
Examples include (a) int x(1+x^2)^3 dx, (b) int x^6 cos(2x^7) dx, (c) int sin(x)cos(x) dx, and (d) int x(1+x)^2 dx. In problem (c), we recall an occasional problem with integrals, and, in problem (d), we show an instance where re-substitution is required.
Lecture 32
Integration by Substitution: Definite Integrals
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Integration by Substitution: Definite Integrals
Calculus: We note how integration by substitution works with definite integrals using the First Fundamental Theorem of Calculus. Two methods are given, and examples used are (a) int_0^1 x(x^2+1)^5 dx, (b) int_0^{pi/4} tan(x) sec^2(x) dx, (c) int_{-1}^1 x(1-x^2)^2 dx, and (d) int_0^2 x(1-x^2)^2 dx.
Lecture 33
Example of Integration by Substitution 1: f(x) = (-x)/[(x+1)-sqrt(x+1)]
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Example of Integration by Substitution 1: f(x) = (-x)/[(x+1)-sqrt(x+1)]
Worked problem in calculus using integration by substitution. Calculate the indefinite integral of (-x) / [(x+1) - sqrt(x+1)]. Steps include a difference of two squares and checking the answer.
Lecture 34
Example of Integration by Substitution 2: f(x) = x^5/(1-x^3)^3
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Example of Integration by Substitution 2: f(x) = x^5/(1-x^3)^3
Worked problem in calculus. Find the indefinite integral of x^5/[(1-x^3)^3]. Methods include integration by substitution and a re-substitution when some terms remain.
Lecture 35
Example of Integration by Substitution 3: f(x) = x^2(1+x)^4 over [0,1]
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Example of Integration by Substitution 3: f(x) = x^2(1+x)^4 over [0,1]
Worked problem in calculus. Compute the definite integral of x^2(1+x)^4 from x=0 to x=1. Integration by substitution gives a useful trick for when the 4 is replaced by higher exponents.
Lecture 36
Example of Integration by Substitution 4: f(x) = (2x+3)/sqrt(2x+1)
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Example of Integration by Substitution 4: f(x) = (2x+3)/sqrt(2x+1)
Calculus. Compute the indefinite integral of (2x+3)/sqrt(2x+1).
Methods include integration by substitution and re-substitution.
Lecture 37
Example of Integration by Substitution 5: f(x) = sin(x)/cos^3(x)
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Example of Integration by Substitution 5: f(x) = sin(x)/cos^3(x)
Calculus: Find the indefinite integral of sin(x)/[cos^3(x)]. Integration by substitution is used. A second approach allows us to use the easily overlooked form [f]^1 f' in the substitution.
Lecture 38
Example of Trapezoid Rule with Error Bound
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Example of Trapezoid Rule with Error Bound
Calculus: The Trapezoid Rule is used to approximate the area under the curve f(x) = (1+x)^2 over the interval [0,2]. A bound for the error in the approximation is also given.
Lecture 39
Example of Simpson's Rule with Error Bound
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Example of Simpson's Rule with Error Bound
Calculus: Simpson's Rule is used to approximate the area under the curve f(x) = sqrt(1 + x) over the interval [0, 1]. An upper bound for the error is also given.