Sin75°/Cos75°+Cos75°/Sin15°=?
问题描述:
Sin75°/Cos75°+Cos75°/Sin15°=?
答
Sin75°/Cos75°+Cos75°/Sin15°= sin(45°+30°) / cos(45°+ 30 °) + 1 .Cos75°与 Sin15°相等= (sin45°cos30°+ cos45°sin30°) / (cos45°cos30°- sin45°sin30°) + 1= (√2/2 * √3/2 + √2/2 * 1/2 ) ...