Discover how to measure angles, distances, and heights using trigonometric ratios and the unit circle. Learn how to use sine, cosine, and tangent to solve real-world problems involving triangles and …

Learn how to use the unit circle to define sine, cosine, and tangent for all real numbers. Created by Sal Khan.

Unit 14: Circles About this unit Explore, prove, and apply important properties of circles that have to do with things like arc length, radians, inscribed angles, and tangents.

I believe the point of the video is to get you to start thinking of the unit circle in terms of radians. Yes, you can convert to degrees, but it is good to have a feel for radians. Knowing that 90° = π/2 and 180° = …

What is the unit circle definition of the trigonometric functions? The unit circle definition allows us to extend the domain of sine and cosine to all real numbers.

The unit circle can be seen as an extension or generalization of SOHCAHTOA, as it provides a broader and more comprehensive understanding of trigonometric functions beyond just right triangles.

Sal finds trigonometric identities for sine and cosine by considering angle rotations on the unit circle.

Sal draws the graph of the tangent function based on the unit circle definition of the function.

Play with the point on the unit circle to see how cosine and secant change together. Notice how when cosine is small, secant is big, and vice versa. It turns out they always multiply to exactly 1 ‍ .

"Are we supposed to assume there are roughly 6.28 radians in a circle and estimate whether each of the answers would be inside of the domain of the function?" Pretty much, actually. Knowing the decimal …