one solution (dont know what to prove, and if the angles are in degrees)
multiply and divide by cos9°.sin63°
the expression reduces to - cos27°.sin189°/cos9°.sin63° = tan9°
one solution (dont know what to prove, and if the angles are in degrees)
multiply and divide by cos9°.sin63°
the expression reduces to - cos27°.sin189°/cos9°.sin63° = tan9°