Videos and lessons to help High School students learn how to explain and use the relationship between the sine and cosine of complementary angles.

sin θ = cos(90 - θ)

Common Core: HSG-SRT.C.7

Related Topics:

Common
Core (Geometry)

Common Core
for Mathematics

Sine and Cosine Relationships of Complementary angles.
Cofunctions

Sine and Cosine of complementary angles are congruent.

Complementary Angle Theorem.

Complementary Angles with Trig Ratios

Complementary angles in trigonometry.

Complementary angles in trig.

Cofunctions of Complementary Angles.

Cofunction Identities

This video explains the cofunction identities and how to determine cofunctions given a function value. Most cofunction values are verified on a calculator.

Rotate to landscape screen format on a mobile phone or small tablet to use the **Mathway** widget, a free math problem solver that **answers your questions with step-by-step explanations**.

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.