Instructional Video11:02
Khan Academy

Trigonometric System Example, Trig Identities and Examples, Trigonometry

10th - 12th
Sal solves a challenging problem that consists of a system of three trigonometric equations and three unknowns.
Instructional Video9:49
Khan Academy

Proof: sin(a+b)=(cos a)(sin b)+(sin a)(cos b)

10th - 12th
Sal proves the sum of angles formula for sine, sin (a+ b) = cos (a) sin (b) + sin (a) cos (b), through a clear but rather non-intuitive proof. The proof is interesting as it uses the SOH-CAH-TOA model and requires one to recall some...
Instructional Video9:22
Khan Academy

Proof: cos(a+b)=(cos a)(cos b)-(sin a)(sin b)

10th - 12th
Using a similar method that he used to prove the sum of angles formula for sine, Sal shows the proof of the cosine sum of angles formula, cos (a+ b) = cos (a) cos (b) - sin (a) sin (b). This proof also uses the SOH-CAH-TOA model and some...
Instructional Video10:01
Khan Academy

Fun Trig Problem

10th - 12th
If solving trigonometric equations is your idea of fun, then this video is correctly titled. Sal uses trigonometric identities, the quadratic formula, and inverse trigonometric functions to solve a trigonometric equation sent in by a...
Instructional Video10:01
Curated OER

Fun Trig Problem

11th - Higher Ed
If solving trigonometric equations is your idea of fun, then this video is correctly titled. Here Sal uses trigonometric identities, the quadratic formula, and inverse trigonometric functions to solve a trigonometric equation sent in by...
Instructional Video1:20
FuseSchool

Area of a Triangle 1/2absinC Proof

9th - 12th Standards
Demonstrate the derivation of the trigonometric area formula for a triangle. Using the base/height formula and the sine ratio, the lesson instructor demonstrates how to combine the two and create the formula A = 1/2absinC. The video...
Instructional Video3:57
3Blue1Brown

Snell's Law Proof Using Springs

9th - 12th Standards
Does light always travel in a straight line? The narrator of a short video discusses the path light travels when going between different mediums and points out that light will want to travel on the path that minimizes the travel time....
Instructional Video
Khan Academy

Khan Academy: Trigonometry: Fun Trig Problem

9th - 10th
Video shows solving an equation with sine and cosine by using a trigonometric identity and solving the resulting quadratic equation. [10:01]
Instructional Video
Khan Academy

Khan Academy: Trigonometry: Trigonometric System Example

9th - 10th
Video demonstrates solving for all possible values of theta for a trigonometric system of three equations. [11:02]
Instructional Video
Math TV

Math tv.com: Trigonometry: Trigonometric Equations Involving Multiple Angles

9th - 10th
The tutorial examines how to find all the degree or radian solutions to trigonometric equations. The learning activity consists of a video with detailed explanations and a worksheet. In the left hand menu, click on Trigonometry,...
Instructional Video
Sophia Learning

Sophia: Solving an Equation by Factoring a Trigonometric Quadratic by Grouping

9th - 10th
Grouping terms in order to factor a quadratic that includes trigonometric expressions is demonstrated here. This lesson is 6 of 7 in the series titled "Solving an Equation by Factoring a Trigonometric Quadratic by Grouping."
Instructional Video
Sophia Learning

Sophia: Solving an Equation by Applying a Half Angle Identity: Lesson 6

9th - 10th
Using a half angle trigonometric identity to help solve an equation is show here. This lesson is 6 of 7 in the series titled "Solving an Equation by Applying a Half Angle Identity."
Instructional Video
Khan Academy

Khan Academy: More Trig Examples: Trigonometric System Example

9th - 10th
Video demonstrates solving for all possible values of theta for a trigonometric system of three equations.
Instructional Video
PatrickJMT

Patrick Jmt: Solving Trigonometric Equations

9th - 10th
Tutorial lesson explores how to solve equations with trigonometry in them. [10:05]
Instructional Video
Study Pug

Study Pug: Solving Trigonometric Equations Involving Multiple Angles

9th - 10th
This video explains how to solve trigonometric equations involving multiple angles. [18:44]
Instructional Video
Study Pug

Study Pug: Solving First Degree Trigonometric Equations

9th - 10th Standards
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...
Instructional Video
Sophia Learning

Sophia: Finding a Common Factor for a Trigonometric Expression: Lesson 5

9th - 10th
The process of factoring a common value or expression from multiple terms in a trigonometric equation is shown here. This lesson is 5 of 7 in the series titled "Finding a Common Factor for a Trigonometric Expression."
Instructional Video
Sophia Learning

Sophia: Finding a Common Factor for a Trigonometric Expression: Lesson 7

9th - 10th
The process of factoring a common value or expression from multiple terms in a trigonometric equation is shown here. This lesson is 7 of 7 in the series titled "Finding a Common Factor for a Trigonometric Expression."
Instructional Video
Sophia Learning

Sophia: Finding a Common Factor for a Trigonometric Expression: Lesson 1

9th - 10th
The process of factoring a common value or expression from multiple terms in a trigonometric equation is shown here. This lesson is 1 of 7 in the series titled "Finding a Common Factor for a Trigonometric Expression."
Instructional Video
Sophia Learning

Sophia: Solving an Equation by Applying a Double Angle Identity: Lesson 2

9th - 10th
Using a double angle trigonometric identity to help solve an equation is show here. This lesson is 2 of 7 in the series titled "Solving an Equation by Applying a Double Angle Identity."
Instructional Video
Sophia Learning

Sophia: Solving an Equation by Applying a Double Angle Identity: Lesson 3

9th - 10th
Using a double angle trigonometric identity to help solve an equation is show here. This lesson is 3 of 7 in the series titled "Solving an Equation by Applying a Double Angle Identity."
Instructional Video
Sophia Learning

Sophia: Solving an Equation by Applying a Double Angle Identity: Lesson 5

9th - 10th
Using a double angle trigonometric identity to help solve an equation is show here. This lesson is 5 of 7 in the series titled "Solving an Equation by Applying a Double Angle Identity."
Instructional Video
Sophia Learning

Sophia: Solving an Equation by Applying a Double Angle Identity: Lesson 7

9th - 10th
Using a double angle trigonometric identity to help solve an equation is show here. This lesson is 7 of 7 in the series titled "Solving an Equation by Applying a Double Angle Identity."
Instructional Video
Sophia Learning

Sophia: Solving an Equation by Applying a Half Angle Identity: Lesson 3

9th - 10th
Using a half angle trigonometric identity to help solve an equation is show here. This lesson is 3 of 7 in the series titled "Solving an Equation by Applying a Half Angle Identity."