Khan Academy
Khan Academy: Linear Algebra: Inverting Matrices (Part 2)
Video example of finding the inverse of a 3 by 3 matrix. Includes using expansion by minors to determine the determinant and finding the matrix of cofactors and adjugate or adjoint matrix. This video also appears in the strand Algebra:...
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Mixed Numbers to Improper Fractions
This video shows how to write a mixed number as an improper fraction. Practice problems are available. [4:26]
Khan Academy
Khan Academy: Algebra: Multiply and Simplify a Radical Expression 2
Video showing how to divide radicals and then simplify the results by using the rules of exponents. [3:07]
Khan Academy
Khan Academy: Algebra: Unit Conversion Example: Drug Dosage
A step-by-step breakdown on how solve a real-world application problem such as drug dosing which involves converting between unit systems as well as units within the same system. Practice problems available. [10:44]
Khan Academy
Khan Academy: Algebra: Complex Numbers: Adding Complex Numbers
Video shows an example of adding complex numbers. Includes link to additional practice problems. [1:11]
Khan Academy
Khan Academy: Geometry: 30 60 90 Triangle Side Ratios Proof
In this video tutorial [6:59], the instructor provides a proof for the relationship among the legs and hypotenuse of 30-60-90 triangles by breaking an equilateral triangle into two congruent triangles and using the Pythagorean threorem.
Khan Academy
Khan Academy: Algebra: Testing a Solution for a System of Equations
This video demonstrates how to test a solution for a system of equations by substituting the values back into each equations. [2:38]
Khan Academy
Khan Academy: Differential Equations: 2nd Order Linear Homogeneous Equations 2
Video shows an example of solving a second order linear homogeneous differential equation. Includes how to write the solution in a general form using the properties of homogeneous equations shown in the previous video. Briefly discusses...
Khan Academy
Khan Academy: Statistics: Alternate Variance Formulas
Video shows using algebra to manipulate the variance formula to arrive at alternate variance formulas. [12:17]
Khan Academy
Khan Academy: Algebra: Multiplying Monomials
Video explains how to express the area of a given rectangle as a monomial. [1:05]
Khan Academy
Khan Academy: Linear Algebra: Column Space of a Matrix
Video defines the column space as a linear combination of the column vectors and relates it to span. Shows that the column space is a valid subspace. Shows several ways to interpret a column space. This video also appears in the strand...
Khan Academy
Khan Academy: Linear Algebra: Projection Onto Subspace With Orthonormal Basis Ex
Video defining a specific orthonormal basis and using the simplified formula found in the previous video to calculate the projection of a vector onto a subspace with the given orthonormal basis. [6:42]
Khan Academy
Khan Academy: Linear Algebra: Coordinates With Respect to Orthonormal Bases
Video showing that the standard basis is an example of an orthonormal basis. Explains how orthonormal bases make good coordinate systems since they make it easy to find coordinates. A general orthonormal basis is defined and then it is...
Khan Academy
Khan Academy: Algebra: Partial Fraction Expansion 1
Video demonstrates how to perform partial fraction expansion on a given rational expression. In the given expression, the degree of the numerator is the same as the degree of the denominator. [11:28]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Conversion Between Metric Units
This video explains the meaning of various metric measurement unit prefixes and how to convert between them. Practice problems are available. [5:16]
Khan Academy
Khan Academy: Algebra: Conversion Between Metric Units
Step-by-step breakdown on how to convert centimeters into dekaliters of the metric system. This video also appears in the strand Arithmetic and Pre-Algebra: Ratios and Proportions. [5:16]
Khan Academy
Khan Academy: Pre Calculus: Benford's Law Explanation
The second video on Benford's Law from the Khan Academy. This video connects Benford's Law to the logarithmic scale in an effort to explain why it holds true, particularly in data that grows exponentially. [6:27]
Khan Academy
Khan Academy: Geometry: Similarity Example Where Same Side Plays Different Roles
Explains how to determine unknown side lengths in a diagram that involves similar triangles where the two triangles share a side and the shared side corresponds to two different sides in each triangle. [6:05]
Khan Academy
Khan Academy: Statistics: Difference of Sample Means Distribution
Video shows visually and reviews notation for sampling distributions of random variables. It then visually shows the distribution of the mean of the difference of two random variables and gives the formulas for the mean and variance of...
Khan Academy
Khan Academy: Linear Algebra: Dot and Cross Product Comparison/intuition
Video first reviews how to find the angle between two vectors, as well as restating the relationship between the cross product and the sine of that angle. Then gives an intuition of what the dot product and the cross product represent....
Khan Academy
Khan Academy: Linear Algebra: Dot and Cross Product Comparison/intuition
Video gives an intuition of what dot product and cross product represent. Also gives a comparison between cross product and dot product of vectors and how they are related. Shows which angles maximize the cross product and dot product....
Khan Academy
Khan Academy: Geometry:sss to Show a Radius Is Perpendicular to Chord It Bisects
Explains how to prove that a radius is perpendicular to a chord that it bisects by using the side-side-side triangle congruence postulate. [8:19]
Khan Academy
Khan Academy: Algebra: Three Equation Application Problem
This video demonstrates how to solve a problem in a geometry context by setting up and solving a systems of equations in three variables. [8:15]
Khan Academy
Khan Academy: Differential Equations: The Convolution and the Laplace Transform
Video gives the convolution theorem showing how the convolution and Laplace transform are related, then shows an example applying the convolution theorem. [13:46]