Question

1.已知集合A={x|1≤x＜4},B={x|x＜a},若A含于B,求实数a的取值集合.

Answer 1

1.已知集合A={x|1≤x＜4},B={x|x＜a},若A含于B,求实数a的取值集合.

a≥4

2.已知M={0,2,b},N={0,2,b},且M=N,求实数b的值.

b²=b 或1, 但b=0不合题意.b=1

3.设集合A={a²,-3,9},B={4,-3,8},若A∩B={4,-3},求实数a的值

A∩B={4,-3},a²=4 , a=±2