InterviewSolution
Saved Bookmarks
| 1. |
General solution of `sin^(2) x-5 sin x cos x -6 cos^(2)x=0` isA. `x=n pi-pi//4, n in Z` onlyB. `npi+tan^(-1) 6, n in Z` onlyC. both (a) and (2)D. none of these |
|
Answer» Correct Answer - C Dividing the given equation by `cos^(2) x`, as `cos x =0` does not satisfy the equation, we have `tan^(2) x-5 tan x -6 =0` or `(tan x+1) (tan x-6)=0` or `tan x=-1 or tan x=6` If `tan x=-1=tan (-pi//4)`, then `x=npi-pi//4, AA n in Z` and, if `tan x=6=tan alpha` (say) `rArr alpha = tan^(-1) 6`, then, `x=n pi +alpha =n pi+tan^(-1) 6, AA n in Z` Hence, `x=npi-(pi//4), n pi + tan^(-1) 6, n in Z`. |
|