S= solve( 'b*(1-2*x1^2)+a*y1 = x2', 'b*(1-2*y1^2)+a*x1 = y2', 'b*(1-2*x2^2)+a*y2 = y1', 'b*(1-2*y2^2)+a*x2 = x1', x1,y1,x2,y2)
Maple俺不会，Matlab求不出来。
谢谢指教。

equ:={ b*(1-2*x1^2)+a*y1 = x2, b*(1-2*y1^2)+a*x1 = y2, b*(1-2*x2^2)+a*y2 = y1, b*(1-2*y2^2)+a*x2 = x1};
solve(equ,{x1,y1,x2,y2});
手机上敲得不知道在电脑上会不会出现中英文混合错误。如果有错你在英文输入模式下把上面代码再输一遍，注意几个标点符号很重要。我估计最终结果可能带有rootof型表达，不过你先试试吧

各位大神，需要求σ的实部和虚部，怎么推导呀

(d*a__01/(a*d-b*c)-b*b__01/(a*d-b*c))*a+(d*a__02/(a*d-b*c)-b*b__02/(a*d-b*c))*c = 0, (d*a__01/(a*d-b*c)-b*b__01/(a*d-b*c))*b+(d*a__02/(a*d-b*c)-b*b__02/(a*d-b*c))*d = 0, (-c*a__01/(a*d-b*c)+a*b__01/(a*d-b*c))*a+(-c*a__02/(a*d-b*c)+a*b__02/(a*d-b*c))*c = 0, (-c*a__01/(a*d-b*c)+a*b__01/(a*d-b*c))*b+(-c*a__02/(a*d-b*c)+a*b__02/(a*d-b*c))*d = 1，这个方程组用maple怎么解啊。