InterviewSolution
Saved Bookmarks
| 1. |
In a `DeltaPQR`. if `3 sinP +4 cosQ=6` and `4sinQ+3cosP=1`, then the angle `R` is equal to:A. `( 5pi)/(6)`B. `(pi)/(6)`C. `(pi)/(4)`D. `(3pi)/(4)` |
|
Answer» Correct Answer - B `3 sin P + 4 cos Q =6" " `(i) `4 sin Q + 3 cos P =1" " `(ii) Squaring and adding (i) and (ii) we get ` sin (P+Q) = (1)/(2)` `rArr P + Q = (pi)/(6) or (5pi)/(6)` `rArr R =(5pi)/(6) or (pi)/(6)` If `R = (5pi)` then `0 lt P, Q lt (pi)/(6)` `rArr cos Q lt 1 and sin P lt (1)/(2)` `rArr 3 sin P + 4 cos Q lt (11)/(2)`, which is not possible So `R= (pi)/(6)` |
|