x^3-5x^2+5x+5=0
2个回答

x^3-5x^2 5x 5=0

这是个一元三次方程,用盛金公式得三个根:

x1=(5-(100^(1/3) 10^(1/3))/3

x2=(5 sin30°[100^(1/3) 10^(1/3)] cos30°[100^(1/3)-10^(1/3)]i)/3

x3=(5 sin30°[100^(1/3) 10^(1/3)]-cos30°[100^(1/3)-10^(1/3)]i)/3