We need to prove that it is equal to tan 9x... Plaza can u help me solve it and send the answer as soon as possible

Friend,the question which u have noted is wrong the correct question should be sinx.sin2x+sin3xsin6x+sin4x.sin13x//sinx.cos2x+sin3x.cos6x+sin4x.cos13x Multiply both numerator and denominator with 22sinx.sin2x+2sin3xsin6x+2sin4x.sin13x//2sinx.cos2x+2sin3xcos6x+2sin4x.cos13xWe know that 2sinAsinB=cos(A-B)-cos(A+B). and 2sinAcosB=sin(A+B)+sin(A-B)On substituting the above formulas ;Numerator=Cosx-cos3x+cos3x-cos9x+cos9x-cos17x=Cosx-cos17x=2sin9xsin8xDenominator =sin3x-sinx+sin9x-sin3x+sin17x-sin9x=Sin17x-sinx=2sin9xcos8xtherefore 2sin9x.sin8x//2cos9x.sin8xtherefore==Tan9xHence proved..