7. explain how the cast rule aids in determining the sign of any trigonometric ratio. 5 marks
7. explain how the cast rule aids in determining the sign of any trigonometric ratio. 5 marks
Answer
Brief Explanations:
The CAST rule is a mnemonic device. It helps in determining the sign of trigonometric ratios based on the quadrant in which the angle lies. In the first quadrant (All), all trigonometric ratios (sine, cosine, tangent) are positive. In the second quadrant (Sin), only sine (and its reciprocal cosecant) is positive. In the third quadrant (Tan), only tangent (and its reciprocal cotangent) is positive. In the fourth quadrant (Cos), only cosine (and its reciprocal secant) is positive.
Answer:
The CAST rule helps determine the sign of trigonometric ratios by indicating which ratios are positive in each quadrant: All (first), Sin (second), Tan (third), Cos (fourth).