sec-xcos-5x-1-0-find-number-of-solution-

Question Number 17100 by virus last updated on 30/Jun/17

\sec x \cos 5 x + 1 = 0

f i n d n u m b e r o f s o l u t i o n

Answered by Tinkutara last updated on 01/Jul/17

\cos 5 x + \cos x = 0

2 \cos 3 x \cos 2 x = 0

Either \cos 3 x = 0 or \cos 2 x = 0

\Rightarrow x = (2 n + 1) \frac{π}{6} or (2 k + 1) \frac{π}{4}

There should be infinite number of

solutions .