Initial Sine and Cosine Definitions
- A B Cron
The sine of theta is the y-value divided by the distance from the origin. The cosine of theta is the x-value divided by the distance from the origin. This applet reduces the distance of (x, y) from the origin to 1. Due to triangle symmetry, the length on the x-axis is the cosine ratio, and the length on the y-axis is the sine ratio. Click on the play button in the lower left to automatic the applet.
Do the cos θ and the sin θ have a maximum value? In which quadrants is cos θ negative? positive? In which quadrants is sin θ negative? positive?