Question

(sin 3theta -1)(2cos2 theta - 1) =0, find the value of theta.​

Answer 1

Answer

Value of theta will be 30°

Solution

let theta as a

Given -

• (sin 3a -1)(2cos 2a -1) = 0

Now either of these two ( sin3a -1 ) or (2 cos 2a -1 ) will be 0 , So

Putting sin3a -1 equivalent to 0

sin 3a -1 = 0

sin3a. = 1

sin 3a. = sin 90°

3a. =. 90°

a. = 90/3

a. = 30 °

Now we can also get this answer by putting the 2nd digit equivalent to 0

2 Cos2a -1 = 0

cos 2a. = 1/2

cos 2a. = cos 60°

2a. = 60°

a. = 60/2

So a = 30°

hope it helps ❤