Question

cos36 sin36 tan36 cos72 sin72 tan72 等于多少?

Answer 1

sin36=[√(10-2√5)]/4

cos36=(√5+1)/4

tan36=sin36/cos36=[√(10-2√5)]/(√5+1)

sin72=2sin36cos36=[√(10-2√5)]*(√5+1)/8

cos72=cos²36-sin²36=(-4+4√5)/16