Saved Bookmarks
| 1. |
If `alpha` and `beta` are solutions of `sin^2 x + a sin x+b=0` as well as that of `cos^2x + c cosx + d =0` then `sin(alpha + beta) ` is equal toA. `(2bd)/(b^(2)+d^(2))`B. `(a^(2)+c^(2))/(2ac)`C. `(b^(2)+d^(2))/(2bd)`D. `(2ac)/(a^(2)+c^(2))` |
|
Answer» Correct Answer - D If `alpha` and `beta` are ………….. According to the given condition, `sin alpha + sin beta = -a` and `cos alpha+cos beta= -c` . `implies 2 sin. (alpha+beta)/(2)cos.(alpha-beta)/(2)= -a &` `2cos.(alpha+beta)/(2)cos.(alpha-beta)/(2)= -c` `implies tan. (alpha+beta)/(2)= (a)/(c ) implies sin. (alpha + beta)` `(2tan.(alpha+beta)/(2))/(1+tan.^(2)(alpha+beta)/(2)) = (2ac)/(a^(2)+c^(2))` |
|