X1²+X2²=什么 X1+X2=3/2 X1X2=-1/2
问题描述:
X1²+X2²=什么 X1+X2=3/2 X1X2=-1/2
答
x1^2 x2^2=(x1 x2)^2-2*x1*x2=13/4
答
X1²+X2²=(X1+X2)²-2X1X2=(3/2)²-2*(-1/2)=13/4