Quadrantal Angles

Move the point to see how the 3 trig ratios change. Pay special attention when the angle is 0°, 90°, 180°, and 270°.

What value of x or y is zero... 1. at 0°? What does this imply about sin(0°),cos(0°) and tan(0°)? 2. at 90°? What does this imply about sin(90°),cos(90°) and tan(90°)? 3. at 180°? What does this imply about sin(180°),cos(180°) and tan(180°)? 4. at 270°? What does this imply about sin(270°),cos(270°) and tan(270°)?