X1+X2=1/X1+1/X2
即:X1+X2=(X1+X2)/X1X2
X1+X2=0时:0=0,等式成立;
当X1+X2≠0时:两边同除以X1+X2得:
1=1/X1X2
所以:X1X2=1
根据韦达定理:
X1+X2=-(2K-3)
X1X2=K²-3
根据前面得:
X1+X2=0,即:-(2K-3)=0
K=3/2
或:X1X2=1
即:K²-3=1
K²=4
K=2或K=-2
判别式=b²-4ac=(2k-3)²-4(k²-3)=4k²-12k+9-4k²+12=-12k+21
-12k+21≥0
12k≤21
k≤7/4
所以K=-2或K=3/2