How do you solve #2sin (3theta) +1=0#?
1 Answer
Jul 1, 2015
Solve f(x) = 2sin 3x + 1 = 0
Explanation:
On the trig unit circle,
sin 3x = - 1/2 -> 3x = 210 deg and 3x = 330 deg
a. 3x = 210 ->
b. 3x = 330 ->
Check:
a. x = 70 deg -> 3x = 210 --> sin 210 = - 1/2 --> 2(-1/2) + 1 = 0. OK
b. x = 110 deg -> 3x = 330--> sin 330 = - 1/2 -> 2(-1/2) + 1 = 0. OK
