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]
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.
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: Trig to Solve the Sides and Angles of a Right Triangle
Worked example using trigonometry to solve for the lengths of the sides of a right triangle given one of the non-right angles.
Khan Academy
Khan Academy: Using Trig to Solve for Missing Information
Worked example using trig ratios to solve for missing information and evaluate other trig ratios.
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: Geometry: Basic Trigonometry
Problems address the equation of a circle, basic trignometry.
Khan Academy
Khan Academy: Basic Trigonometric Ratios: Example: The Six Trig Ratios
Worked example where we walk through finding the major trigonometric ratios.
Khan Academy
Khan Academy: Basic Trigonometric Ratios: Basic Trigonometry
Video introducing the basic trigonometry ratios sine, cosine, and tangent.
Khan Academy
Khan Academy: Trigonometry: Tangent Identities: Periodicity
Sal solves a problem by considering the periodicity of the tangent function. [4:01]
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...