使用泰勒公式的Maclaurin 展开式.sin(x) = x - x^3 / 3!+ x^5 / 5!+ ...+ ((-1)^(m-1))*((x^(2m-1)) / (2m - 1)!) + ((-1)^(m))*(cos(θx)*(x^(2m+1)) / (2m + 1)!)cos(x) = 1 - x^2 / 2!+ x^4 / 4!+ ...+ ((-1)^(m)...