Khan Academy
Khan Academy: Algebra: Conic Sections: Intro to Circles
A video lesson introducing the standard form for the equation of a circle. Starts out with a circle centered at the origin and then discusses the changes to both the equation and the graph when a circle is centered elsewhere. Illustrates...
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Khan Academy: Algebra: Parallel Line Equation
This video demonstrates how to find the equation of a line when given a point on the line and the equation of a line parallel to that line. The equation given is not in slope-intercept form. [4:24]
Khan Academy
Khan Academy: Algebra: Percent Problems
This video works through examples on how to convert a fraction to a percent and a percent to a fraction. Then, it applies this knowledge by demonstrating how to solve algebraic percent problems. Practice problems available. This video is...
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Khan Academy: Algebra: Word Problem Solving 3
A video that demonstrates how to write and solve equations for several different types of algebraic word problems. This is another percent example. This video is also found in the strand Algebra: ck12.org. [11:06]
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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: Biology: Mitosis, Meiosis and Sexual Reproduction
An overview of sexual reproduction and how mitosis and meiosis occur to form a particular species. [18:23]
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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]
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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]
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Khan Academy: Algebra: Conic Sections: Focus and Directrix of a Parabola 2
A video lesson that provides instruction on finding the focus and directrix of a parabola. The majority of the video shows how the formulas for the focus and directrix are derived. Then a concrete example is given and the formulas are...
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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]
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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: 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...
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Khan Academy: E1 and E2 Reactions: Carbocations and Rearrangements
An in-depth look at carbocations and rearrangements of carbons in organic chemistry. [11:26]
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Khan Academy: E1 and E2 Reactions: E2 Elimination: Stereospecificity
In this video, Sal explains stereospecificity. [8:01]
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]
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Khan Academy: Small X Approximation for Small Kc
Understand when the small x approximation is useful for solving equilibrium problems. Find an example using the small x approximation when Kc is small. [9:37]
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Khan Academy: Small X Approximation for Large Kc
Guidelines and worked examples for using the small x approximation to solve equilibrium problems with large Kc values. [14:04]