佐助知道真相后怎么样:如何判断一元四次方程是否有解？

现实的方法是令F(x)等于那个方程的左边。这样对F(x)求导，令导数为零解方程就可以求出所有的极值来，再加上x趋于正无穷和负无穷时的F(正无穷)和F(负无穷)的正负。将F(正无穷)和F(负无穷)也看做是两个极值点。这样比较相邻相极点的正负就可以确定原方程在这两个极值点之间是否有根。这样就确定了根的个数了。
语文水平不行，如果没看懂，把你遇到的题写出来，我帮你做一次估计你就明白了。

很麻烦的，共有四个根，列出其中一个，很长，Maple算的。很恐怖的。x1＝

-1/4*b/a-1/12*3^(1/2)/a*((3*b^2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)-8*c*a*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)+2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(2/3)*a-24*d*b*a+96*e*a^2+8*a*c^2)/(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3))^(1/2)+1/12/a*(-(-18*b^2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)*((3*b^2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)-8*c*a*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)+2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(2/3)*a-24*d*b*a+96*e*a^2+8*a*c^2)/(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3))^(1/2)+48*c*a*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)*((3*b^2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)-8*c*a*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)+2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(2/3)*a-24*d*b*a+96*e*a^2+8*a*c^2)/(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3))^(1/2)+6*((3*b^2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)-8*c*a*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)+2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(2/3)*a-24*d*b*a+96*e*a^2+8*a*c^2)/(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3))^(1/2)*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(2/3)*a-72*((3*b^2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)-8*c*a*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)+2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(2/3)*a-24*d*b*a+96*e*a^2+8*a*c^2)/(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3))^(1/2)*d*b*a+288*((3*b^2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)-8*c*a*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)+2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(2/3)*a-24*d*b*a+96*e*a^2+8*a*c^2)/(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3))^(1/2)*e*a^2+24*((3*b^2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)-8*c*a*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)+2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(2/3)*a-24*d*b*a+96*e*a^2+8*a*c^2)/(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3))^(1/2)*a*c^2-144*3^(1/2)*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)*d*a^2-18*3^(1/2)*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)*b^3+72*3^(1/2)*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)*b*c*a)/(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)/((3*b^2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)-8*c*a*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3)+2*(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(2/3)*a-24*d*b*a+96*e*a^2+8*a*c^2)/(-36*c*d*b-288*e*c*a+108*d^2*a+108*e*b^2+8*c^3+12*(18*d^2*b^2*e*a+576*d*b*e^2*a^2-54*c*d^3*b*a-54*c*d*b^3*e-432*e*c*a^2*d^2-432*e^2*c*a*b^2+12*d^3*b^3-768*e^3*a^3+81*e^2*b^4-3*d^2*b^2*c^2+384*e^2*a^2*c^2-48*e*a*c^4+12*d^2*a*c^3+12*e*b^2*c^3+81*d^4*a^2+240*d*b*e*a*c^2)^(1/2))^(1/3))^(1/2))^(1/2)

一元四次方程有求根公式吧，好像五次以上就没了。求根公式的虚数部分系数为零则为实根。

五次及五次以上的方程一般只能求近似解。
一般的 计算方法 书上都有教导，你可以找一本参考。

随便一本有关矩阵的书里都有这个题目.

图书馆借一本看看吧.

解出来就知道嘞