Key Concepts from Calculus I, Second Half

Notes from Calculus I. I created these notes to help get me through Calculus I. My notes end somewhere around the end of Volume 1 of the OpenStax Textbook, because that's all we used in class.

Rules for Indefinite Integrals

Properties of Indefinite Integrals

Let and be antiderivatives of and , respectively, and let be any real number.

Sums and Differences

Constant Multiples

Definition of Partitions

A set of points for with , which divides the interval into subintervals of the form , is called a partition of . If the subintervals all have the same width, the set of points forms a regular partition (or uniform partition ) of the interval .

So, to create regular partitions on a closed interval, we start by selecting evenly spaced points along

And then index each boundary point between partitions.

Rule: Left-Endpoint approximation

On each subinterval for construct a rectangle with width and height equal to , which is the function value at the left endpoint of the subinterval. Then the area of the rectangle is . Adding the areas of all these rectangles, we get an approximate value for . We use the notation to denote that this is a left-endpoint approximation of using subintervals.

or, in terms of sigma notation:

Rule: Right-Endpoint approximation

repeat steps above, but this time set rectangle heights to be equal to . Then the area of the rectangle is . We use the notation to denote that this is a right-endpoint approximation of using subintervals.

or, in terms of sigma notation:

Riemann sum

Let be defined on a closed interval and let be any partition of . Let be the width of each subinterval and for each , let be any point in. A riemann sum is defined for as

Area under the Curve

Let be a continuous, nonnegative function on an interval , and let be a Riemann sum for with a regular partition . Then, the area under the curve on is given by

If is a function defined on an interval , the definite integral of from to

is given by

provided the limit exists. If this limit exists, the function is said to be integrable on , or is an integrable function.

Properties of the Definite Integral

Average Value of a Function

Let be continuous over the interval . Then the average

The Fundamental Theorem of Calculus, Part 1

If is continuous over an interval , and the function is defined by

then over

The Fundamental Theorem of Calculus, Part 2

If is continuous over the interval and is any antiderivative of then

Subtitution for indefinite integrals

Let where is continuous over an interval, let be continuous over the corresponding range, of , and let be an antiderivative of . Then,

Substitution for indefinite integrals

Let where is continuous over an interval , and let be continuous over the corresponding range of . Then,

Integrals of Exponential Functions

Integral formulas involving logs

Integral formulas resulting in inverse trig functions

Integration by parts

or, if u = f(x) and v = g(x)

Choosing and

can be chosen by selecting the first type of function appearing in the expression which appears in the LIATE

  • Logarithmic functions
  • Inverse Trig functions
  • Algebraic functions
  • Trig functions
  • Exponential functions

Integration by parts for definite integrals

Let and be functions with continuous derivatives on . Then

Applications of Integrals

Finding the area between two curves

Let and be continuous functions such that over an interval . Let denote the region bounded above by the graph of , below the graph of , and on the left and right by lines and , respectively. Then the area of is given by

Integral Definition of natural logarithm

for , we define the natural logarithm by

Derivative of the Natural Logarithm

For , the derivative of the natural logarithm is given by

Differential equations

A differential equation is an equation involving an unknown function and one or more of its derivatives. A solution to a differential equation is a function that satisfies the differential equation when and its derivatives are substituted into the equation.

the order of a differential equation is the highest order of any derivative of the unknown function that appears in the equation.

A separable differential equation is any equation that can be written in the form


These notes are based on the OpenStax Calculus Textbook

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