已知集合A=[x|x^2=1},B={x|ax=1}.若B是A的子集,求实数a的值
问题描述:
已知集合A=[x|x^2=1},B={x|ax=1}.若B是A的子集,求实数a的值
答
A=[x|x^2=1}
= { -1,1}
B is subset of A
then
ax =1
a = 1/x ( x = -1 or 1 )
= -1 or 1 #