Khan Academy
Solving Equations 1
Sal demonstrates how to solve an equation. He begins by saying that the variable needs to be isolated. He shows how to move numbers on either side of the equal sign to isolate the variable. He also shows how to verify answers by plugging...
Khan Academy
Solving a Quadratic by Factoring
Solving quadratics by factoring is the main concept in this video. Several examples are shown with positive numbers and with negative numbers. The instructor demonstrates how to set the factored equation to zero to solve the quadratic....
Curated OER
Slope and Y-Intercept Intuition
The instructor uses a computer graphing program to illustrate how a line changes slope by manipulating the slope values in the equation. He also manipulates the y-intercept value to see where the line crosses the y-axis.
Curated OER
Slope and Rate of Change
Introducing slope as "a way of measuring the inclination of a line," Sal endeavors to provide a working knowledge of slope problems and problem solving. The video is framed as a review, but could be a good way to fill any holes in...
Khan Academy
Simple Equations
Basic algebraic equations of the form Ax=B are dissected. Sal encourages viewers to fully understand what the equations represent prior to learning how to manipulate them. Furthermore, he teaches students how to solve the equations...
Khan Academy
Similar Triangles (Part 2)
Building on concepts in the first part of the series on similar triangles, installment number two explores how to find the values for given angles in a triangle. These problems are solved by using algebra and ratios. A step-by-step...
Khan Academy
Scientific Notation Examples
The problems in this video contain additional examples of scientific notation, continued from the previous presentation. Viewers have the opportunity to see Sal work through several more problems using the same techniques he has been...
Khan Academy
Rhombus Diagonals
Delving into a proof that the diagonals of a rhombus are perpendicular to each other, this lecture evaluates the angles and sides of this figure. It would serve as a great test preparation activity.
Khan Academy
Refraction of Seismic Waves
Mr. Khan uses a metaphor of a car to help explain the change in direction of waves as they hit a boundary between two mediums. He then goes on to explain the relationship between the structure and density of the earth and the behavior of...
Khan Academy
Recognizing Odd and Even Functions
This video gives a formal definition of odd and even functions, as well as, an intuitive feeling for how they are different. By looking at the graphs of both types of functions, Sal shows the reflection properties of both functions....
Khan Academy
Recognizing Linear Relationships
Starting with a set of values for the x and y variables, this video shows how to tell whether these points determine a linear or non-linear function. Sal first defines linear functions in terms of the change in y over the change in x,...
Khan Academy
Range, Variance and Standard Deviation as Measures of Dispersion
Continuing his conversation about data sets from the previous video, Sal introduces range, variance, and standard deviation as means of dispersion. Those who are advancing in algebra or who are beginning a statistics class will benefit...
Curated OER
Pythagorean Theorem All
As the second in a series on the Pythagorean Theorem, this lecture delves into some more difficult problems. Primarily, it examines the process for finding the value of a hypotenuse. It is particularly helpful because the example problem...
Khan Academy
Patterns in Sequences 2
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...
Khan Academy
Patterns in Sequences 1
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...
Khan Academy
Parallel Lines 2
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.
Curated OER
Introduction to Logarithms Properties
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...
Curated OER
Intro to 30-60-90 Triangles
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...
Curated OER
Finding the 100th Term in a Sequence
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...
Curated OER
Example of Solving for a Variable
Sal uses the formula for perimeter to show how the variables can be moved around to solve a problem. He demonstrates a few different ways to do this.
Curated OER
Equations of Sequence Patterns
An example of writing an algebraic equation of the pattern of blocks that grows at each iteration is shown in this video. Sal shows how to find the pattern by looking at the iteration number and number of blocks. He then continues this...
Curated OER
Domain of a Function
We look at a number of different examples of functions and see what their domain is. Sal writes the domain in set notion and shows how different functions can have different input values that cause the function to be undefined.
Curated OER
What is the domain of a function?
After defining a simple function from a word problem, a short video shows how one could find the domain and the range of that function. The instruction reinforces the definitions of domain and range with a concrete example.
Curated OER
Connection between even and odd numbers and functions
Are odd numbers connected to odd functions and even numbers to even functions? This video tries to clarify that connection. It also talks about functions that are neither odd nor even to give a more intuitive feeling about classifying...