Saved Bookmarks
| 1. |
If `sin2A=2sinA cosAand sin20^(@)=K, " then the value of " cos20^(@)cos80^(@)cos160^(@)`=__________.A. KB. `-sqrt(1-k^(2)`C. `sqrt(1-k^(2))/(8)`D. `-sqrt(1-k^(2))/(8)` |
|
Answer» Correct Answer - B (i) Multiply and divide the given expression with `sin20^(@)` (ii) Use `sin^(2) A = 2sinA cosA`. `sin(180-A) = sinA`. |
|