the cosine of a sum formula 127 videos

The Distance Formula in Polar Coordinates
Precalculus Polar Coordinates and Complex Numbers
How to derive the distance formula for polar coordinates.
polar coordinates the law of cosines triangles 
Midpoint Formula
Algebra 2 Graphs of Linear Equations
How to find the midpoint of two points.
midpoint formula 
Solving Formulas
Geometry Area
How to strategize about solving formulas for variables; how to solve the area of a rectangle formula for base and height; how to solve the area of a triangle formula for base and for height.
formulas isolating a variable rectangle area triangle area trapezoid area regular polygon area 
The Definitions of Sine and Cosine
Trigonometry Trigonometric Functions
How we define sine and cosine for all angle measures using the unit circle.
sine cosine right triangle definitions of sine and cosine angles in standard position unit circle definitions of sine and cosine 
The Definitions of Sine and Cosine
Precalculus Trigonometric Functions
How we define sine and cosine for all angle measures using the unit circle.
sine cosine right triangle definitions of sine and cosine angles in standard position unit circle definitions of sine and cosine 
The Inverse Cosine Function
Precalculus Advanced Trigonometry
How to restrict the domain of cosine so it will have an inverse function.
inverse functions one to one inverse cosine arccosine 
The Inverse Cosine Function
Trigonometry Advanced Trigonometry
How to restrict the domain of cosine so it will have an inverse function.
inverse functions one to one inverse cosine arccosine 
Equiangular Polygon Sums
Geometry Polygons
How to find the measure of one angle in any equiangular or regular polygon.
equiangular regular congruent triangles sum 
Find an Equation for the Sine or Cosine Wave
Trigonometry Trigonometric Functions
How to identify the graph of a stretched cosine curve.
sine cosine period amplitude intercepts turning points 
Find an Equation for the Sine or Cosine Wave
Precalculus Trigonometric Functions
How to identify the graph of a stretched cosine curve.
sine cosine period amplitude intercepts turning points 
Evaluating Sine and Cosine at Other Special Angles
Trigonometry Trigonometric Functions
How to measure the sine and cosine of 150.
sine cosine unit circle definitions of sine and cosine angles in standard position reference angles 
Evaluating Sine and Cosine at Other Special Angles
Precalculus Trigonometric Functions
How to measure the sine and cosine of 150.
sine cosine unit circle definitions of sine and cosine angles in standard position reference angles 
Evaluating Sine and Cosine at Special Acute Angles
Trigonometry Trigonometric Functions
How do we measure sine and cosine of pi/4?
sine cosine unit circle definitions of sine and cosine angles in standard position 
Evaluating Sine and Cosine at Special Acute Angles
Precalculus Trigonometric Functions
How do we measure sine and cosine of pi/4?
sine cosine unit circle definitions of sine and cosine angles in standard position 
Geometric Series
Algebra 2 Sequences and Series
How to find the sum of a geometric series.
geometric series sum of a geometric sequence rate infinite sum finite sum 
Geometric Series
Precalculus Sequences and Series
How to find the sum of a geometric series.
geometric series sum of a geometric sequence rate infinite sum finite sum 
The Midpoint and Distance Formulas in 3D
Precalculus Vectors and Parametric Equations
How to derive the formula for the midpoint of a segment in three dimensions.
position vectors the vector from point a to point b the midpoint formula vector addition scalar multiplication 
Arithmetic Series
Algebra 2 Sequences and Series
How to find the sum of an arithmetic series.
partial sums arithmetic series sum of an arithmetic sequence 
Arithmetic Series
Precalculus Sequences and Series
How to find the sum of an arithmetic series.
partial sums arithmetic series sum of an arithmetic sequence