Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • NCERT
  • Find the general solution of the following equation sin 2x + cos x = 0

Q (7) Find the general solution of the following equation 

\small \sin 2x + \cos x = 0

Answers (1)

best_answer

sin2x + cosx = 0
We know that 
sin2x = 2sinxcosx
So, 
2sinxcosx + cosx = 0
cosx(2sinx + 1) = 0
So, we can say that either 

cosx = 0                                       or                           2sinx + 1 = 0
    x=(2n+1)\frac{\pi}{2}                                                          sinx =\sin\frac{7\pi}{6}
                                                                                               x=n\pi +(-1)^{n}\frac{7\pi}{6}
Therefore, the general solution is

 x=(2n+1)\frac{\pi}{2}    or   n\pi +(-1)^{n}\frac{7\pi}{6} \ where \ n\in Z 

Posted by

manish

View full answer

Crack CUET with india's "Best Teachers"

  • HD Video Lectures
  • Unlimited Mock Tests
  • Faculty Support
cuet_ads

Similar Questions

Trending Articles/News

anam-khan

PM Modi's Pariksha Pe Charcha 2025 to be held next month, registrations open till January 14
anam-khan

CBSE Board Exams 2025: Online portal for availing exemptions by CWSN students opens
anam-khan

Board Exams: States agree to equivalence; no question paper ‘jumbling’ from next year, says PARAKH CEO

Latest Question