Khan Academy
Khan Academy: Geometry: Proof Sum of Measures of Angles in a Triangle Are 180
Proof that the sum of the angles in a triangle is 180 using the relationship of angles formed when parallel lines are cut by a transversal. This video also appears in the Geometry: Triangles strand. [6:31]
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Khan Academy: Trigonometry: Graph of the Sine Function
Video showing how to derive the graph of the sine function from the unit circle. Includes link to additional practice problems. [7:44]
Khan Academy
Khan Academy: Statistics: Introduction to Random Variables
Video explains random variables, gives examples of what they are used for and explains the difference from traditional variables. Explains the difference between discrete and continuous random variables. Gives examples of using a random...
Khan Academy
Khan Academy: Statistics: Expected Value E(x)
Video explains the relationship between expected value and population mean and provides an example of calculating expected value using frequencies. [14:53]
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Khan Academy: Statistics: Variance of Differences of Random Variables
Video reviews the notation of the expected value and variance of random variables. It then explains the expected value and variance of the sum of two random variables and explains why the variance of the difference of random variables is...
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Khan Academy: Geometry: Area and Perimeter
Explains how to calculate the area of rectangles, squares, and triangles, in addition to the perimeter of rectangles and squares. Practice problems available. [12:20]
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Khan Academy: Linear Algebra: Vector Dot Product and Vector Length
Video first reviews vector addition and multiplying by a scalar multiple. Gives notation for dot product and shows example of calculating the dot product of vectors. Then gives the formula for vector length and gives examples of using...
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Khan Academy: Linear Algebra: Vector Triangle Inequality
Video first reviews the Cauchy-Schwarz inequality. Then shows a proof of the triangle inequality for vectors and relates it to the triangle inequality from 2-dimensional geometry. [18:53]
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Khan Academy: Pre Calculus: Polar Coordinates 2
The sequel to Polar Coordinates 1 from the Khan Academy, this segment goes through some examples on converting polar coordinates to rectangular coordinates and converting a Cartesian equation to a polar equation. Graphing is also used to...
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Khan Academy: Algebra: Graphs Using Slope Intercept Form
This video demonstrates how to find the equation of a line in slope-intercept form given the graph of the line. There are three examples. Practice problems available. This video is also found in the strand Algebra: ck12.org. [11:11]
Khan Academy
Khan Academy: Algebra: Complex Numbers:calculate I Raised to Arbitrary Exponents
Video shows how to write i raised to various powers as simpler problems using exponent rules and the simple powers of i rules shown in the previous video. Includes link to additional practice problems. [6:20]
Khan Academy
Khan Academy: Algebra: Complex Numbers: I as the Principal Root of 1
Video shows the logic behind why some believe that saying i is the principal root of -1 is wrong. Explains why the logic is faulty. Explains more technically the meaning of principal root. [6:44]
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Khan Academy: Linear Algebra: Unit Vectors
Video first introduces what a unit vector is. Shows how to construct a unit vector using scalars. Shows notation for unit vectors. [6:59]
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Khan Academy: Arithmetic and Pre Algebra: Subtraction Word Problem
This video shows how to solve a subtraction word problem using borrowing or regrouping. Practice problems are available. [5:09]
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Khan Academy: Algebra: Quadratic Functions 1
Video graphing a quadratic function by evaluating it for seven different values and plotting the resulting points. [4:04]
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Khan Academy: Algebra I: Linear Equations: Absolute Value Equation Example 2
This video demonstrates how to solve an equation that contains absolute values. It also shows how to check your answer and plot it on a number line. [6:32]
Khan Academy
Khan Academy: Trigonometry: Graphing Trig Functions
Video showing how to graph the sine and cosine functions from their equations with modifications to the amplitude and period. Also gives an example of determining the trigonometric function using the features of the graph. Includes link...
Khan Academy
Khan Academy: Algebra: Ratio and Proportion
Step-by-step instructions on how to solve ratio and proportion word problems. This video is also found in the strand Algebra: ck12.org. [10:25]
Khan Academy
Khan Academy: Algebra: Monomial Greatest Common Factor
Video defines what a greatest common factor is and demonstrates how to determine the greatest common factor of two given monomials. [3:13]
Khan Academy
Khan Academy: Geometry: Ca Geometry: Deducing Angle Measures
Demonstrates how to solve five different problems from a released California Geometry state test that involve finding the measures of angles in different polygons. This video also appears in the Geometry: Worked Examples section. [10:58]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Multiplication 7: More Examples
A video showing more examples of multiplication with multi-digit numbers. [6:18]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Rounding Decimals
This video demonstrates how to round a decimal number to the nearest tenth. Practice problems are available. [1:26]
Khan Academy
Khan Academy: Arithmetic and Pre Algebra: Rounding Whole Numbers 1
This video shows how to round a five-digit number to the nearest hundred using a number line. Practice problems are available. [4:23]
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Khan Academy: Algebra: Evaluating a Polynomial at a Given Value
Demonstrates how to evaluate a polynomial for a given variable value. [1:09]