sin15°
=sin(30°/2)
=√[(1-cos30°)/2]
=√{[1-(√3)/2]/2}
=√[(2-√3)/4]
=[√(2-√3)]/2
=[√(8-4√3)]/4
=[√(√6-√2)^2]/4
=(√6-√2)/4
pe=op*sin15°=3(√6-√2)/2 说明:pe是直角边,15度的对边,op是斜边.
sin15°
=sin(30°/2)
=√[(1-cos30°)/2]
=√{[1-(√3)/2]/2}
=√[(2-√3)/4]
=[√(2-√3)]/2
=[√(8-4√3)]/4
=[√(√6-√2)^2]/4
=(√6-√2)/4
pe=op*sin15°=3(√6-√2)/2 说明:pe是直角边,15度的对边,op是斜边.