x1,x2是一元二次方程2x^2-5x+1=0的两个根
x1+x2=5/2 x1*x2=1/2
(x1)^2+(x2)^2
=(x1+x2)^2-2x1x2
=(5/2)^2-2*1/2
=25/4-1
=21/4
设X1,X2是一元二次方程2X^2-5X+1=0的两个根,利用根与系数的关系,求下列各式的值
设X1,X2是一元二次方程2X^2-5X+1=0的两个根,利用根与系数的关系,求下列各式的值
数学人气:607 ℃时间:2019-11-05 02:29:05
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