方程 (-(q^5+5*p*q^4+10*p^2*q^3+10*p^3*q^2+5*p^4*q+p^5+7776*c)/((q+p)^(2/3)*(2^(10/3)*3^(10/3)*q+2^(10/3)*3^(10/3)*p))) 的解为 p
解 1
p = -q-6*%e^(2*%i*%pi/5)*c^(1/5)
解 2
p = -q-6*%e^(4*%i*%pi/5)*c^(1/5)
解 3
p = -%e^-(4*%i*%pi/5)*(%e^(4*%i*%pi/5)*q+6*c^(1/5))
解 4
p = -%e^-(2*%i*%pi/5)*(%e^(2*%i*%pi/5)*q+6*c^(1/5))
解 5
p = -q-6*c^(1/5)
【当p不等于0时,即c<0时】
q=0
【当p=0时,也就是c>0时】
q=-3*2^(2/3)*(abs(c) +c)^(1/3)
变形为:
2^(10/3)*3^(10/3)*x^5+(q+p)^(1/3)*(-q^3-3*p*q^2-3*p^2*q-p^3)*x^3+2^(10/3)*3^(10/3)*c*x^2-(q+p)^(1/3)*(c*q^3+3*c*p*q^2+3*c*p^2*q+c*p^3)=0
再次变形为:
x^5+(((q+p)^(1/3)*(-q^3-3*p*q^2-3*p^2*q-p^3))/ (2^(10/3)*3^(10/3)))*x^3+x^2-((q+p)^(1/3)*(c*q^3+3*c*p*q^2+3*c*p^2*q+c*p^3))/ (2^(10/3)*3^(10/3))=0
方程
x^5+(((q+p)^(1/3)*(-q^3-3*p*q^2-3*p^2*q-p^3))/(2^(10/3)*3^(10/3)))*x^3+x^2-((q+p)^(1/3)*(c*q^3+3*c*p*q^2+3*c*p^2*q+c*p^3))/(2^(10/3)*3^(10/3))=0的解为 x
解 1
x = -(q+p)^(5/3)/(2^(5/3)*3^(5/3))
解 2
x = (q+p)^(5/3)/(2^(5/3)*3^(5/3))
解 3
x = -(sqrt(3)*%i-1)*c^(1/3)/2
解 4
x = (sqrt(3)*%i+1)*c^(1/3)/2
解 5
x = -c^(1/3)
方程 x^5+(((q+p)^(1/3)*(-q^3-3*p*q^2-3*p^2*q-p^3))/(2^(10/3)*3^(10/3)))*x^3+x^2-((q+p)^(1/3)*(c*q^3+3*c*p*q^2+3*c*p^2*q+c*p^3))/(2^(10/3)*3^(10/3))=0 的解为 c
c = ((2^(10/3)*3^(10/3)*x^5+(q+p)^(1/3)*(-q^3-3*p*q^2-3*p^2*q-p^3)*x^3+2^(10/3)*3^(10/3)*x^2)/((q+p)^(1/3)*(q^3+3*p*q^2+3*p^2*q+p^3)))
方程 x^5+f*x^3+c*x^2+c*f=0 的解为 x
解 1
x = -sqrt(-f)
解 2
x = sqrt(-f)
解 3
x = -(sqrt(3)*%i-1)*c^(1/3)/2