Question

Question #e30c5

Answer 1

Solve 2sin 3x.cos x - cos x = 0
Ans: `(pi)/2; (3pi)/2; (pi)/18; and (5pi)/18`

Explanation:

2sin 3x.cos x - cos x = 0
cos x (2sin 3x - 1) = 0
a. cos x = 0 --> `x = (pi)/2` and `x = (3pi)/2`

b. sin 3x = 1/2 --> 3x = pi/6 --> `x = pi/18` and
`3x = (pi - pi/6) = (5pi)/6` --> `x = 5pi/18`