Who is asking: Student
sin3x cos3x _____ - _____ = 2 sinx cosx
x = the variableHi Eric,
If you know the formulas for sin 3x and cos 3x, then it's easy. You can work the formulas out for yourself. Use
sin(a+b) = sin(a)cos(b) + cos(a)sin(b)
cos(a+b) = cos(a)cos(b) - sin(a)sin(b)
with 3x = 2x + x.