Mathematics Education Trigonometry lesson 9 – Definition of sine and cosine using the unit circle By Magic Monk on Saturday, October 13, 2018 In this lesson, we talk about why it is that, for any point on the unit circle, x=cos(theta) and y=sin(theta). education mathematics steemiteducation steempress steemstem Previous Post Next Post Related Posts Mathematics Education Vector applications question – Elastic collision, momentum, and kinetic energy Mathematics Education Vectors lesson 21 – Basic vector operations in Geogebra Mathematics Education Vectors lesson 20 – drawing vectors in Geogebra