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楼主 |
发表于 2014-9-20 13:05
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本帖最后由 风花飘飘 于 2014-9-20 21:26 编辑
缺4次项方程:x^5+a*x^3+b*x^2+c*x+d=0---------(0) 的5个根,其和等于0。
不妨设为:x1=2*r-s+u+v; x2=-r+s-u-v; x3=-r-u-v; x4=u; x5=v
表达式1:
(x-2*r+s-u-v)*(x+r-s+u+v)*(x+r+u+v)=x^3+(v+u)*x^2+(-v^2+(-2*u+2*s-4*r)*v-u^2+(2*s-4*r)*u-s^2+3*r*s-3*r^2)*x-v^3+(-3*u+2*s-4*r)*v^2+(-3*u^2+(4*s-8*r)*u-s^2+5*r*s-5*r^2)*v-u^3+(2*s-4*r)*u^2+(-s^2+5*r*s-5*r^2)*u-r*s^2+3*r^2*s-2*r^3
表达式2:
(x-u)*(x-v)= x^2+(-v-u)*x+u*v
表达式2乘以表达式1:
=x^5+(-2*v^2+(-3*u+2*s-4*r)*v-2*u^2+(2*s-4*r)*u-s^2+3*r*s-3*r^2)*x^3+(u*v^2+(u^2+2*r*s-2*r^2)*v+(2*r*s-2*r^2)*u-r*s^2+3*r^2*s-2*r^3)*x^2+(v^4+(3*u-2*s+4*r)*v^3+(4*u^2+(8*r-4*s)*u+s^2-5*r*s+5*r^2)*v^2+(3*u^3+(8*r-4*s)*u^2+(s^2-7*r*s+7*r^2)*u+r*s^2-3*r^2*s+2*r^3)*v+u^4+(4*r-2*s)*u^3+(s^2-5*r*s+5*r^2)*u^2+(r*s^2-3*r^2*s+2*r^3)*u)*x-u*v^4+((2*s-4*r)*u-3*u^2)*v^3+(-3*u^3+(4*s-8*r)*u^2+(-s^2+5*r*s-5*r^2)*u)*v^2+(-u^4+(2*s-4*r)*u^3+(-s^2+5*r*s-5*r^2)*u^2+(-r*s^2+3*r^2*s-2*r^3)*u)*v
对于缺4次项方程:
令:z1=x-x1; z2=x-x2; z3=x-x3; z4=x-x4; z5=x-x5---------(2.1)
将(2.1)分别代入(0),分别得到关于zi的(i=1,2,3,4,5)共5个方程:
毫无疑问,zi是 (i=1,2,3,4,5)等于0滴!
所以,这5个方程的常数表达式必须是等于0滴!
<1>;
(z+2*r-s+u+v)^5+a*(z+2*r-s+u+v)^3+b*(z+2*r-s+u+v)^2+c*(z+2*r-s+u+v)+d
=z^5+(5*v+5*u-5*s+10*r)*z^4+(10*v^2+(20*u-20*s+40*r)*v+10*u^2+(40*r-20*s)*u+10*s^2-40*r*s+40*r^2+a)*z^3+(10*v^3+(30*u-30*s+60*r)*v^2+(30*u^2+(120*r-60*s)*u+30*s^2-120*r*s+120*r^2+3*a)*v+10*u^3+(60*r-30*s)*u^2+(30*s^2-120*r*s+120*r^2+3*a)*u-10*s^3+60*r*s^2+(-120*r^2-3*a)*s+80*r^3+6*a*r+b)*z^2+(5*v^4+(20*u-20*s+40*r)*v^3+(30*u^2+(120*r-60*s)*u+30*s^2-120*r*s+120*r^2+3*a)*v^2+(20*u^3+(120*r-60*s)*u^2+(60*s^2-240*r*s+240*r^2+6*a)*u-20*s^3+120*r*s^2+(-240*r^2-6*a)*s+160*r^3+12*a*r+2*b)*v+5*u^4+(40*r-20*s)*u^3+(30*s^2-120*r*s+120*r^2+3*a)*u^2+(-20*s^3+120*r*s^2+(-240*r^2-6*a)*s+160*r^3+12*a*r+2*b)*u+5*s^4-40*r*s^3+(120*r^2+3*a)*s^2+(-160*r^3-12*a*r-2*b)*s+80*r^4+12*a*r^2+4*b*r+c)*z+v^5+(5*u-5*s+10*r)*v^4+(10*u^2+(40*r-20*s)*u+10*s^2-40*r*s+40*r^2+a)*v^3+(10*u^3+(60*r-30*s)*u^2+(30*s^2-120*r*s+120*r^2+3*a)*u-10*s^3+60*r*s^2+(-120*r^2-3*a)*s+80*r^3+6*a*r+b)*v^2+(5*u^4+(40*r-20*s)*u^3+(30*s^2-120*r*s+120*r^2+3*a)*u^2+(-20*s^3+120*r*s^2+(-240*r^2-6*a)*s+160*r^3+12*a*r+2*b)*u+5*s^4-40*r*s^3+(120*r^2+3*a)*s^2+(-160*r^3-12*a*r-2*b)*s+80*r^4+12*a*r^2+4*b*r+c)*v+u^5+(10*r-5*s)*u^4+(10*s^2-40*r*s+40*r^2+a)*u^3+(-10*s^3+60*r*s^2+(-120*r^2-3*a)*s+80*r^3+6*a*r+b)*u^2+(5*s^4-40*r*s^3+(120*r^2+3*a)*s^2+(-160*r^3-12*a*r-2*b)*s+80*r^4+12*a*r^2+4*b*r+c)*u-s^5+10*r*s^4+(-40*r^2-a)*s^3+(80*r^3+6*a*r+b)*s^2+(-80*r^4-12*a*r^2-4*b*r-c)*s+32*r^5+8*a*r^3+4*b*r^2+2*c*r+d
<2>;
(z-r+s-u-v)^5+a*(z-r+s-u-v)^3+b*(z-r+s-u-v)^2+c*(z-r+s-u-v)+d
=z^5+(-5*v-5*u+5*s-5*r)*z^4+(10*v^2+(20*u-20*s+20*r)*v+10*u^2+(20*r-20*s)*u+10*s^2-20*r*s+10*r^2+a)*z^3+(-10*v^3+(-30*u+30*s-30*r)*v^2+(-30*u^2+(60*s-60*r)*u-30*s^2+60*r*s-30*r^2-3*a)*v-10*u^3+(30*s-30*r)*u^2+(-30*s^2+60*r*s-30*r^2-3*a)*u+10*s^3-30*r*s^2+(30*r^2+3*a)*s-10*r^3-3*a*r+b)*z^2+(5*v^4+(20*u-20*s+20*r)*v^3+(30*u^2+(60*r-60*s)*u+30*s^2-60*r*s+30*r^2+3*a)*v^2+(20*u^3+(60*r-60*s)*u^2+(60*s^2-120*r*s+60*r^2+6*a)*u-20*s^3+60*r*s^2+(-60*r^2-6*a)*s+20*r^3+6*a*r-2*b)*v+5*u^4+(20*r-20*s)*u^3+(30*s^2-60*r*s+30*r^2+3*a)*u^2+(-20*s^3+60*r*s^2+(-60*r^2-6*a)*s+20*r^3+6*a*r-2*b)*u+5*s^4-20*r*s^3+(30*r^2+3*a)*s^2+(-20*r^3-6*a*r+2*b)*s+5*r^4+3*a*r^2-2*b*r+c)*z-v^5+(-5*u+5*s-5*r)*v^4+(-10*u^2+(20*s-20*r)*u-10*s^2+20*r*s-10*r^2-a)*v^3+(-10*u^3+(30*s-30*r)*u^2+(-30*s^2+60*r*s-30*r^2-3*a)*u+10*s^3-30*r*s^2+(30*r^2+3*a)*s-10*r^3-3*a*r+b)*v^2+(-5*u^4+(20*s-20*r)*u^3+(-30*s^2+60*r*s-30*r^2-3*a)*u^2+(20*s^3-60*r*s^2+(60*r^2+6*a)*s-20*r^3-6*a*r+2*b)*u-5*s^4+20*r*s^3+(-30*r^2-3*a)*s^2+(20*r^3+6*a*r-2*b)*s-5*r^4-3*a*r^2+2*b*r-c)*v-u^5+(5*s-5*r)*u^4+(-10*s^2+20*r*s-10*r^2-a)*u^3+(10*s^3-30*r*s^2+(30*r^2+3*a)*s-10*r^3-3*a*r+b)*u^2+(-5*s^4+20*r*s^3+(-30*r^2-3*a)*s^2+(20*r^3+6*a*r-2*b)*s-5*r^4-3*a*r^2+2*b*r-c)*u+s^5-5*r*s^4+(10*r^2+a)*s^3+(-10*r^3-3*a*r+b)*s^2+(5*r^4+3*a*r^2-2*b*r+c)*s-r^5-a*r^3+b*r^2-c*r+d
<3>:
(z-r-u-v)^5+a*(z-r-u-v)^3+b*(z-r-u-v)^2+c*(z-r-u-v)+d
=z^5+(-5*v-5*u-5*r)*z^4+(10*v^2+(20*u+20*r)*v+10*u^2+20*r*u+10*r^2+a)*z^3+(-10*v^3+(-30*u-30*r)*v^2+(-30*u^2-60*r*u-30*r^2-3*a)*v-10*u^3-30*r*u^2+(-30*r^2-3*a)*u-10*r^3-3*a*r+b)*z^2+(5*v^4+(20*u+20*r)*v^3+(30*u^2+60*r*u+30*r^2+3*a)*v^2+(20*u^3+60*r*u^2+(60*r^2+6*a)*u+20*r^3+6*a*r-2*b)*v+5*u^4+20*r*u^3+(30*r^2+3*a)*u^2+(20*r^3+6*a*r-2*b)*u+5*r^4+3*a*r^2-2*b*r+c)*z-v^5+(-5*u-5*r)*v^4+(-10*u^2-20*r*u-10*r^2-a)*v^3+(-10*u^3-30*r*u^2+(-30*r^2-3*a)*u-10*r^3-3*a*r+b)*v^2+(-5*u^4-20*r*u^3+(-30*r^2-3*a)*u^2+(-20*r^3-6*a*r+2*b)*u-5*r^4-3*a*r^2+2*b*r-c)*v-u^5-5*r*u^4+(-10*r^2-a)*u^3+(-10*r^3-3*a*r+b)*u^2+(-5*r^4-3*a*r^2+2*b*r-c)*u-r^5-a*r^3+b*r^2-c*r+d
<4>:
(z+u)^5+a*(z+u)^3+b*(z+u)^2+c*(z+u)+d
= z^5+5*u*z^4+(10*u^2+a)*z^3+(10*u^3+3*a*u+b)*z^2+(5*u^4+3*a*u^2+2*b*u+c)*z+u^5+a*u^3+b*u^2+c*u+d
<5>:
(z+v)^5+a*(z+v)^3+b*(z+v)^2+c*(z+v)+d
= z^5+5*v*z^4+(10*v^2+a)*z^3+(10*v^3+3*a*v+b)*z^2+(5*v^4+3*a*v^2+2*b*v+c)*z+v^5+a*v^3+b*v^2+c*v+d
即常数项等于0:
<1>: v^5+(5*u-5*s+10*r)*v^4+(10*u^2+(40*r-20*s)*u+10*s^2-40*r*s+40*r^2+a)*v^3+(10*u^3+(60*r-30*s)*u^2+(30*s^2-120*r*s+120*r^2+3*a)*u-10*s^3+60*r*s^2+(-120*r^2-3*a)*s+80*r^3+6*a*r+b)*v^2+(5*u^4+(40*r-20*s)*u^3+(30*s^2-120*r*s+120*r^2+3*a)*u^2+(-20*s^3+120*r*s^2+(-240*r^2-6*a)*s+160*r^3+12*a*r+2*b)*u+5*s^4-40*r*s^3+(120*r^2+3*a)*s^2+(-160*r^3-12*a*r-2*b)*s+80*r^4+12*a*r^2+4*b*r+c)*v+u^5+(10*r-5*s)*u^4+(10*s^2-40*r*s+40*r^2+a)*u^3+(-10*s^3+60*r*s^2+(-120*r^2-3*a)*s+80*r^3+6*a*r+b)*u^2+(5*s^4-40*r*s^3+(120*r^2+3*a)*s^2+(-160*r^3-12*a*r-2*b)*s+80*r^4+12*a*r^2+4*b*r+c)*u-s^5+10*r*s^4+(-40*r^2-a)*s^3+(80*r^3+6*a*r+b)*s^2+(-80*r^4-12*a*r^2-4*b*r-c)*s+32*r^5+8*a*r^3+4*b*r^2+2*c*r+d=0
<2>:
-v^5+(-5*u+5*s-5*r)*v^4+(-10*u^2+(20*s-20*r)*u-10*s^2+20*r*s-10*r^2-a)*v^3+(-10*u^3+(30*s-30*r)*u^2+(-30*s^2+60*r*s-30*r^2-3*a)*u+10*s^3-30*r*s^2+(30*r^2+3*a)*s-10*r^3-3*a*r+b)*v^2+(-5*u^4+(20*s-20*r)*u^3+(-30*s^2+60*r*s-30*r^2-3*a)*u^2+(20*s^3-60*r*s^2+(60*r^2+6*a)*s-20*r^3-6*a*r+2*b)*u-5*s^4+20*r*s^3+(-30*r^2-3*a)*s^2+(20*r^3+6*a*r-2*b)*s-5*r^4-3*a*r^2+2*b*r-c)*v-u^5+(5*s-5*r)*u^4+(-10*s^2+20*r*s-10*r^2-a)*u^3+(10*s^3-30*r*s^2+(30*r^2+3*a)*s-10*r^3-3*a*r+b)*u^2+(-5*s^4+20*r*s^3+(-30*r^2-3*a)*s^2+(20*r^3+6*a*r-2*b)*s-5*r^4-3*a*r^2+2*b*r-c)*u+s^5-5*r*s^4+(10*r^2+a)*s^3+(-10*r^3-3*a*r+b)*s^2+(5*r^4+3*a*r^2-2*b*r+c)*s-r^5-a*r^3+b*r^2-c*r+d =0
<3>:
-v^5+(-5*u-5*r)*v^4+(-10*u^2-20*r*u-10*r^2-a)*v^3+(-10*u^3-30*r*u^2+(-30*r^2-3*a)*u-10*r^3-3*a*r+b)*v^2+(-5*u^4-20*r*u^3+(-30*r^2-3*a)*u^2+(-20*r^3-6*a*r+2*b)*u-5*r^4-3*a*r^2+2*b*r-c)*v-u^5-5*r*u^4+(-10*r^2-a)*u^3+(-10*r^3-3*a*r+b)*u^2+(-5*r^4-3*a*r^2+2*b*r-c)*u-r^5-a*r^3+b*r^2-c*r+d=0
<4>:
u^5+a*u^3+b*u^2+c*u+d=0
<5>:
v^5+a*v^3+b*v^2+c*v+d
【降次过程】:
1、<1> + <2>得r的一元5次式<6>
2、将<4>与<5>代入<3>消去u的5次项与v的5次项,得r的一元5次式<7>
3、联立<6>与<7>消去r的5次项,
降次成功!
<1>+<2>=<6>:
5*r*v^4+(20*r*u-20*r*s+30*r^2)*v^3+(30*r*u^2+(90*r^2-60*r*s)*u+30*r*s^2-90*r^2*s+70*r^3+3*a*r+2*b)*v^2+(20*r*u^3+(90*r^2-60*r*s)*u^2+(60*r*s^2-180*r^2*s+140*r^3+6*a*r+4*b)*u-20*r*s^3+90*r^2*s^2+(-140*r^3-6*a*r-4*b)*s+75*r^4+9*a*r^2+6*b*r)*v+5*r*u^4+(30*r^2-20*r*s)*u^3+(30*r*s^2-90*r^2*s+70*r^3+3*a*r+2*b)*u^2+(-20*r*s^3+90*r^2*s^2+(-140*r^3-6*a*r-4*b)*s+75*r^4+9*a*r^2+6*b*r)*u+5*r*s^4-30*r^2*s^3+(70*r^3+3*a*r+2*b)*s^2+(-75*r^4-9*a*r^2-6*b*r)*s+31*r^5+7*a*r^3+5*b*r^2+c*r+2*d=0
<4>与<5>代入<3>=<7>:
a*v^3+b*v^2+c*v+d+(-5*u-5*r)*v^4+(-10*u^2-20*r*u-10*r^2-a)*v^3+(-10*u^3-30*r*u^2+(-30*r^2-3*a)*u-10*r^3-3*a*r+b)*v^2+(-5*u^4-20*r*u^3+(-30*r^2-3*a)*u^2+(-20*r^3-6*a*r+2*b)*u-5*r^4-3*a*r^2+2*b*r-c)*v+a*u^3+b*u^2+c*u+d-5*r*u^4+(-10*r^2-a)*u^3+(-10*r^3-3*a*r+b)*u^2+(-5*r^4-3*a*r^2+2*b*r-c)*u-r^5-a*r^3+b*r^2-c*r+d=0
<6>+31*<7>=<8>:
^^^^^^^^^^^
<8>是一个不含5次项的可解方程!
(待续……)
【以y^5-5*x-2=0为例】
<1>: v^5+(5*u-5*s+10*r)*v^4+(10*u^2+(40*r-20*s)*u+10*s^2-40*r*s+40*r^2)*v^3+(10*u^3+(60*r-30*s)*u^2+(30*s^2-120*r*s+120*r^2)*u-10*s^3+60*r*s^2+(-120*r^2)*s+80*r^3)*v^2+(5*u^4+(40*r-20*s)*u^3+(30*s^2-120*r*s+120*r^2)*u^2+(-20*s^3+120*r*s^2+(-240*r^2)*s+160*r^3)*u+5*s^4-40*r*s^3+(120*r^2)*s^2+(-160*r^3)*s+80*r^4-5)*v+u^5+(10*r-5*s)*u^4+(10*s^2-40*r*s+40*r^2)*u^3+(-10*s^3+60*r*s^2+(-120*r^2)*s+80*r^3)*u^2+(5*s^4-40*r*s^3+(120*r^2)*s^2+(-160*r^3)*s+80*r^4-5)*u-s^5+10*r*s^4+(-40*r^2)*s^3+(80*r^3)*s^2+(-80*r^4+5)*s+32*r^5-10*r-2=0
<2>:
-v^5+(-5*u+5*s-5*r)*v^4+(-10*u^2+(20*s-20*r)*u-10*s^2+20*r*s-10*r^2)*v^3+(-10*u^3+(30*s-30*r)*u^2+(-30*s^2+60*r*s-30*r^2)*u+10*s^3-30*r*s^2+(30*r^2)*s-10*r^3)*v^2+(-5*u^4+(20*s-20*r)*u^3+(-30*s^2+60*r*s-30*r^2)*u^2+(20*s^3-60*r*s^2+(60*r^2)*s-20*r^3)*u-5*s^4+20*r*s^3+(-30*r^2)*s^2+(20*r^3)*s-5*r^4+5)*v-u^5+(5*s-5*r)*u^4+(-10*s^2+20*r*s-10*r^2)*u^3+(10*s^3-30*r*s^2+(30*r^2)*s-10*r^3)*u^2+(-5*s^4+20*r*s^3+(-30*r^2)*s^2+(20*r^3)*s-5*r^4+5)*u+s^5-5*r*s^4+(10*r^2)*s^3+(-10*r^3)*s^2+(5*r^4-5)*s-r^5+5*r-2 =0
<3>:
-v^5+(-5*u-5*r)*v^4+(-10*u^2-20*r*u-10*r^2)*v^3+(-10*u^3-30*r*u^2+(-30*r^2)*u-10*r^3)*v^2+(-5*u^4-20*r*u^3+(-30*r^2)*u^2+(-20*r^3)*u-5*r^4+5)*v-u^5-5*r*u^4+(-10*r^2)*u^3+(-10*r^3)*u^2+(-5*r^4+5)*u-r^5+5*r-2=0
<4>:
u^5-5*u-2=0
<5>:
v^5-5*v-2=0
(继续辗转降次…………)
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