若集合A={a|二次方程x^2-2x+a=0有实根}B={a|二次方程ax^2-x+1=0无实根},求A∩B和AUB
热心网友
A={a|二次方程x^2-2x+a=0有实根} ={a|4-4a大于等于0} ={a|a≤1}B={a|二次方程ax^2-x+1=0无实根} ={a|1-4a小于0} ={a|a≥1/4}所以A∩B=1/4≤a≤1AUB=R
若集合A={a|二次方程x^2-2x+a=0有实根}B={a|二次方程ax^2-x+1=0无实根},求A∩B和AUB
A={a|二次方程x^2-2x+a=0有实根} ={a|4-4a大于等于0} ={a|a≤1}B={a|二次方程ax^2-x+1=0无实根} ={a|1-4a小于0} ={a|a≥1/4}所以A∩B=1/4≤a≤1AUB=R