Flipped Math
Unit Circle and Radians
Measure angles is easy as pi. Pupils review special right triangles to find exact values for trigonometric functions. Scholars learn about radians and how they connect to measurements in degrees. They find exact and approximate values of...
Krista King Math
Pythagorean Theorem
A YouTube video efficiently describes the process of using the Pythagorean Theorem. It includes an example of finding the hypotenuse and another that finds the length of a leg.
Khan Academy
Khan Academy: Trigonometry: Trig Identities Part 3
Video expands upon trigonometric identities derived in previous videos. Identities in this lesson include sine and cosine of the opposite of an angle, sine of an angle plus pi divided by two, and the sine of the difference of two angles....
Khan Academy
Khan Academy: Trigonometry: Proof: Cos(a+b)=(cos A)(cos B) (Sin A)(sin B)
Video demonstrating the proof for the formula for the cosine of the sum of two angles. Includes link to additional practice problems. [9:22]
Khan Academy
Khan Academy: Trigonometry: Proof: Sin(a+b)=(cos A)(sin B) + (Sin A)(cos B)
Video demonstrating the proof for the formula for the sine of the sum of two angles. Includes link to additional practice problems. [9:48]
Khan Academy
Khan Academy: Trigonometry: Trig Identities Part 2
Video deriving the double angle formulas for sine and cosine as well as the start of finding the cosine of the opposite of an angle. Reviews basic trigonometric ratio definitions and some basic trigonometric identities. [9:57]
Khan Academy
Khan Academy: Trigonometry: Trigonometry Identity Review/fun
Video showing how to derive additional trigonometric identities, including the double angle formulas, from the sine and cosine of the sum and difference of two angles. Includes link to additional practice problems. [11:07]
Math TV
Math tv.com: Trigonometry: Identities and Formulas
The video proves trigonometric identities. The learning resource consists of a video tutorial with detailed examples and a worksheet with practice problems. Find Identities and Formulas under Trigonometry in the left hand menu.
Math TV
Math tv.com: Trigonometric Functions: More on Identities
Students learn about the six trigonometric identities. The learning resource consists of a video tutorial and a worksheet with practice problems. In the left hand menu, click Trigonometry, Trigonometric Functions, More on Identities.
Khan Academy
Khan Academy: Trig Identities: Trigonometric Identities
Video showing how to derive two basic trigonometric identities.
Khan Academy
Khan Academy: Basic Trigonometric Ratios: Using Trig Functions Part Ii
A couple of more examples of using Trig functions to solve the sides of a triangle. This video use the basic trigonometric functions to determine unknown side lengths of a right triangle. Example shows using trigonometry as well as the...
Khan Academy
Khan Academy: Trig Identities: Proof: Cos(a+b) = (Cos A)(cos B) (Sin A)(sin B)
Video demonstrating the proof for the formula for the cosine of the sum of two angles.
Khan Academy
Khan Academy: Trig Identities: Proof: Sin(a+b) = (Cos A)(sin B) + (Sin A)(cos B)
Video demonstrating the proof for the formula for the sine of the sum of two angles.
Khan Academy
Khan Academy: Basic Trigonometric Ratios: Basic Trigonometry Ii
A few more examples using SOH CAH TOA. Examples of finding sine, cosine and tangent for two different right triangles, including finding side lengths by the Pythagorean Theorem and rationalizing the denominator.
Khan Academy
Khan Academy: Trigonometry: Sine & Cosine Identities: Periodicity
Sal finds trigonometric identities for sine and cosine by considering angle rotations on the unit circle. [6:13]
Khan Academy
Khan Academy: Trigonometry: Tangent Identities: Periodicity
Sal solves a problem by considering the periodicity of the tangent function. [4:01]
Other
Trigonometric Functions f.tf.4
In this teacher-created video, trigonometric functions are developed and explored by changing one of the angles in a right triangle. [10:57]
Study Pug
Study Pug: Double Angle Identities
In this lesson, you will learn how to make use of the double-angle identities, a.k.a. double-angle formulas to find the sine and cosine of a double angle. It's hard to simplify complex trigonometric functions without these formulas. [6:23]
Study Pug
Study Pug: Quotient Identities and Reciprocal Identities
Don't be scared by all the trigonometric identities formulas! This video will show you how to easily simplify and prove quotient identities and reciprocal identities. [7:27]
Study Pug
Study Pug: Solving First Degree Trigonometric Equations
Trigonometric equations are just equations that feature the trigonometric ratios such as sine and cosine on the variable "x". Because of the presence of these trigonometric functions, solving these equations becomes a little more...
Khan Academy
Khan Academy: Solving for an Angle With the Law of Cosines
Sal is given a triangle with all side lengths but no angle measure, and he finds one of the angle measures using the law of cosines.
Sophia Learning
Sophia: Solving a Pythagorean Identity for Cosine: Lesson 2
In this lesson, students will be shown how to solve a Pythagorean identity for cosine. It is 2 of 8 in the series titled "Solving a Pythagorean Identity for Cosine." [2:37]
Sophia Learning
Sophia: Solving a Pythagorean Identity for Cosine: Lesson 4
In this lesson, students will be shown how to solve a Pythagorean identity for cosine. It is 4 of 8 in the series titled "Solving a Pythagorean Identity for Cosine." [1:30]
Sophia Learning
Sophia: Solving a Pythagorean Identity for Cosine: Lesson 6
In this lesson, students will be shown how to solve a Pythagorean identity for cosine. It is 6 of 8 in the series titled "Solving a Pythagorean Identity for Cosine." [2:25]