InterviewSolution
Saved Bookmarks
| 1. |
The value of \(\frac{cos^3 20° - cos^3 70°}{sin^3 70° - sin^3 20°}\) is A. 1/2 B. 1/√2 C. 1 D.2 |
|
Answer» \(\frac{cos^3 20° - cos^3 70°}{sin^3 70° - sin^3 20°}\) = \(\frac{cos^3 20° - cos^3 (90°-20°)}{sin^3 (90°-20°) - sin^3 20°}\) \(\frac{cos^3 20° - sin^3 20°}{cos^3 20° - sin^3 60°}\) = 1 |
|