集合m={y|y=x^2+1,x∈r},n={t|t=5-x^2,x∈r},则m∩n=,

Question

集合m={y|y=x^2+1,x∈r},n={t|t=5-x^2,x∈r},则m∩n=,

Answer 1

集合m∩n即是求两条抛物线交点的纵坐标的集合
由y=x^2+1=5-x^2 解得x=±√2
此时,y=x^2+1=5-x^2=3
∴m∩n={3}