cosx=1-x^2/2!+x^4/4!-…+〖(-1)〗^n/(2n)! x^2n+…N从0到无穷负一的N次方比上2N的阶层再乘以X的2N次方。用公式:f(x)=f(0)+f '(0)x+f ''(0)x^2/2!+f '''(0)x^3/3!+f ''''(0)x^4/4!+........f(0)=1f '=-2sinxcosx=-sin(2x) f '(0)=0f ''=-2cos(2x) f ''(0)=-2f '''=4sin(2x) f '''(0)=0f ''''=8cos(2x) f ''''(0)=8f(x) = 1-x^2+3x^4-..........元素输入值的集合X被称为f的定义域;可能的输出值的集合Y被...