Find all solutions to the equation sin(3x)cosx-sinx cos(3x)=0 on the interval [0,2pi]

a- x=0,pi/4,pi/2,3pi/4,pi,3pi/2,2pi
b- x=0,pi/2,pi,3pi/2,2pi
c- x=0,pi,2pi
d- x=0,pi/2,3pi/2

Cos(x)Cos(3x) + sin(x)sin(3x)=0 [0,2pi]

x= pi/4, 3pi/4, 5pi/4, 7pi/4

explanation:For those who have a different answer choice along with the question.

option 1

data plot with   3 dots over 33, 1 dot over 34, 2 dots over 35, no dot over 36, 1 dot over 37, 2 dots over 38, 4 dots over 39, and 2 dot over 40.

b is 38 degrees.

a is 52 degrees.

this is because if b is 38 and a is 14 degrees more than b than 38+14=52 and 52+38=90 degrees. hope this .