Question

Solve : 2cos(x)sin(3x)=sin(4x)+1

Answer 1

There is an easier way, We know that sin C + sin D = 2 .sin ((C+D) /2)cos ((C -D)/2)

Hence the equation reduces to Sin 4x + Sin 2x = Sin4x + 1
Sin 2x = 1 => x = pi / 4

Answer 2

Thank you!