sin(alpha) + sin(3alpha) + sin(5alpha) / cos(alpha) + cos(3alpha) + cos(5alpha)
= 2sin(4alpha)cos(alpha) - 2sin(4alpha)sin(alpha) / 2cos(4alpha)cos(alpha) - 2cos(4alpha)sin(alpha)
= tan(4*alpha)
sin(alpha) + sin(3alpha) + sin(5alpha) / cos(alpha) + cos(3alpha) + cos(5alpha)
= 2sin(4alpha)cos(alpha) - 2sin(4alpha)sin(alpha) / 2cos(4alpha)cos(alpha) - 2cos(4alpha)sin(alpha)
= tan(4*alpha)