Brian McLogan
How to evaluate for cos when given the value of sine with a right triangle
👉 Learn how to evaluate the six trigonometric functions given some constraints. When given the value of one trigonometric function, we can use a right triangle with one of its legs on the x-axis and the other leg, perpendicular to the...
Khan Academy
Introduction to the Unit Circle, Trigonometry
In this video, Sal shows how the sine and cosine of an angle are defined on the unit circle. He inscribes a 30-60-90 triangle in the unit circle and explains how to use SOH-CAH-TOA to find the circle's coordinates.