设全集是实数R,A={x丨2x²-5x-3≤0},B={x丨x²+a

设全集是实数R,A={x丨2x²-5x-3≤0},B={x丨x²+a
设全集是实数R,A={x丨2x²-5x-3≤0},B={x丨x²+a

设全集是实数R,A={x丨2x²-5x-3≤0},B={x丨x²+a
对于集合A,
不等式2x²-5x-3≤0
解得,-1/2≤ x ≤ 3
∴ A= [-1/2 ,3]
对于集合B,
(i) 若a≥0,那么 B=∅
(ii) 若a