matlab 开4次方根 matlab中计算四次方方程a*x^4+b*x+c=0的实数根.

共回答了13个问题采纳率：84.6%

syms a x b c

y = a*x^4+b*x+c;

Y = solve(y, 'x')

结果如下：

ans =

1/12*6^(1/2)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)+1/12*(-(6*12^(1/3)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)*((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+24*12^(2/3)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)*c*a+72*b*6^(1/2)*((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3)/(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2))^(1/2)

1/12*6^(1/2)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)-1/12*(-(6*12^(1/3)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)*((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+24*12^(2/3)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)*c*a+72*b*6^(1/2)*((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3)/(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2))^(1/2)

-1/12*6^(1/2)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)+1/12*(-(6*12^(1/3)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)*((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+24*12^(2/3)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)*c*a-72*b*6^(1/2)*((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3)/(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2))^(1/2)

-1/12*6^(1/2)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)-1/12*(-(6*12^(1/3)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)*((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+24*12^(2/3)*(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2)*c*a-72*b*6^(1/2)*((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3)/(12^(1/3)*(((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(2/3)+4*c*12^(1/3)*a)/a/((9*b^2+(-768*c^3*a+81*b^4)^(1/2))*a)^(1/3))^(1/2))^(1/2)

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