0.819152044……
-45.183
Sin55° = 0.81915204428899
用计算器, 简单, 先按sin键, 后按50再按=得出sin55°=0.819152
tan(55度)=1.428148007=1又(289/675) sin(55度)=0.819152044=77/94
首先,55度=55*Pi/180 < 1 利用泰勒公式展开 sinx = x - x^3/(3!) + x^5/(5!) - ..
88分之17除以55分之34=17/88*55/34=5/16 (16分之5)不能简便
0.809016994
0.82214400.3018152