This video looks again at finding the algebraic pattern in sequences. In the example, we are looking at a figure where a number of toothpicks (or lines) are added each time, and you need to find how many toothpicks will be in the 50th...

Faced with a series of numbers we need to find the next few values of the sequence. This short video shows an example of finding the next values in a sequence where we need to find the pattern of adding a specific number each time to...

Can you tell, algebraically, if three lines are parallel? In this video, Sal demonstrates how to rewrite linear equations in slope-intercept form and compare the slope of each line.

Starting with a point (focus) and a line below the point (directrix), in this video, Sal tries to find the set of all points (locus) equidistant to the point and the line. He shows, using the distance formula, that indeed, we have an...

Sal gets to the heart of the matter in this video, clarifying that it's important to understand math "so you can actually apply it in life later on and not have relearn everything every time." True to his word, Sal demonstrates ways to...

Sal begins his explanation of limits with a few basic examples and takes a more intuitive point of view before looking at a formal mathematical definition in later videos. He starts by introducing the notation for limits and describes...

Here is a simple tutorial on the difference between simple and compound interest. In it, Sal describes what interest is, defines the vocabulary of principle and interest rate. He also models year-by-year the amount of money owed under...

Starting from a brief look at functions and the mapping of domains to ranges, Sal starts out with an intuitive sense of what a function inverse is. He then, using an example, shows how to find the inverse of a function and also shows how...

As the fourth part of a series on the Pythagorean Theorem, Sal continues an exploration of the ways to calculate the length of sides of a right triangle using algebra. He also explores using this theorem to solve problems involving a...

In this video, Sal shows again how to write an equation of a conic section in standard form and identify the conic section it represents. This time, his example is of a hyperbola (not centered at the origin), which he also graphs.

After watching this video, you should be able to write an equation of a conic section in standard form, and identify the conic section from its equation. In an example problem, Sal reviews how to complete the square and graph an ellipse...

If solving trigonometric equations is your idea of fun, then this video is correctly titled. Here Sal uses trigonometric identities, the quadratic formula, and inverse trigonometric functions to solve a trigonometric equation sent in by...

Continuing from a previous video, Sal takes the discussion of the focus and directrix of parabola further. Given the parabola, y=x2, he derives the focus and directrix by matching parts of the equation he found earlier. He then, comes up...

The foci of an ellipse are explored in this video. First, foci are shown as the two points on the major axis such that the sum of the distance from a point on the ellipse and the foci points is the same as the distance from any point on...

In this video, Sal defines the vertex and the foci of a hyperbola, and shows how to locate both. By comparing the hyperbola to an ellipse throughout the video, the listener sees the similarities between these two conic sections. This...

The example problem is this video has a sequence of numbers that decrease by a fixed amount with each iteration, and one needs to find the 100th number in the sequence. Sal shows the listener how to find the pattern between the number...