[zhangqicai2007]

对第二个方程：
>> solve('x^3-cos(1-y)=0','x')
ans =
cos(-1+y)^(1/3)
-1/2*cos(-1+y)^(1/3)+1/2*i*3^(1/2)*cos(-1+y)^(1/3)
-1/2*cos(-1+y)^(1/3)-1/2*i*3^(1/2)*cos(-1+y)^(1/3)
>> solve('x^3-cos(1-y)=0','y')
ans =
1+acos(x^3)
对第一个方程就不行了。