Monday February 6, 2012

Solving Calculus Limits Example

Computing calculus limits often involves using an algebraic trick. In this post we’ll look at the example of a ratio of two polynomials. In this case you’ll want to factor the polynomials so that you can eliminate one of the troubling terms. Here’s an example:

If you just set x = 2, you get 0/0. However [...]

Integration by parts with limits

Integration by parts with limits is really the same as integration by parts with indefinite integrals until the very end of your calculation. Let’s see how to do integration by parts with limits with an example:

Its always a good idea to start out writing the integration by parts formula:

For now, we can simply ignore [...]

Integration by parts example (with u-substitution)

In some cases, integration by parts has to be used with another technique like u-substitution. For example lets do

Its always a good idea to start out writing the integration by parts formula:

Since taking the derivative of x would just give 1, we’ll take that to be u. So

This integral must be done using u-substitution. [...]

Integration by u-Substitution

Integration by u-substitution is a technique that helps us evaluate many integrals that can’t be done using elementary techniques. That is, we know that several “basic” integrals can be written down by inspection once you learn what the rules are. For example using the power rule you know that:

But what if you had:

This type of [...]

Integration by Parts with Trig Functions

Integration by parts can be used to integrate the product of a trig function with an exponential. For example, consider:

First let’s recall the integration by parts formula:

The trick is to pick u and v in such a way that

is a simpler expression. In this case, try

Then

(ignore constants of integration for now, we’ll add it [...]