Mnemonic Device
- CAST
Explanation
to remember the CAST Rule for trigonometric functions. Go counterclockwise, starting from the bottom right quadrant of graph axes.
- C is the area where the angle is positive for Cosine.
- A is the area where the angle is positive for all trigonometric functions.
- S is the area where the angle is positive for Sine.
- T is the area where the angle is positive for Tangent.
Additional Note
Always measure from the x-axis to the angle line.