As the point P moves anticlockwise around the circle from 0°, the angle θ changes. The values of cos θ and sin θ also change. The graphs of y = sin θ and y = cos θ can be plotted.

Anna F. DeJarnette, Students' Conceptions of Sine and Cosine Functions When Representing Periodic Motion in a Visual Programming Environment, Journal for Research in Mathematics Education, Vol. 49, No ...

Not only one cosine function per time period, but also a mixture of cosine functions can be used to describe the seasonal pattern. Adjustment for confounding effects is possible. Conclusions-This ...

GCSE Edexcel Trigonometry - Edexcel Trigonometric graphs - Higher The three trigonometric ratios; sine, cosine and tangent are used to calculate angles and lengths in right-angled triangles. The ...