Guest

The number of solutions of equation is equal to: (A) (B) (C) (D)

The number of solutions of equation  is equal to:
(A)                             (B)                             (C)                             (D)

Grade:11

1 Answers

Arun
25750 Points
3 years ago
Dear student
 
On simplicity
 
We get
LHS
 
Cos theta + cos 3 theta +.....cos 17 theta
 
Sin (9 theta)* cos 9theta/sin theta
 
 = Sin18 theta/2sin tgeta = ½
 
Sinn18 theta = sin theta
 
18 theta = nπ + (-1)ⁿ theta
 
Now make case for n off and even

Think You Can Provide A Better Answer ?

ASK QUESTION

Get your questions answered by the expert for free