3:
b: x1^2+x2^2=12
=>(x1+x2)^2-2x1x2=12
=>(2m+2)^2-4m=12
=>4m^2+4m+4=12
=>m^2+m+1=3
=>(m+2)(m-1)=0
=>m=1;m=-2
2:
b: =>|x1|-|x2|=m+3-|-1|=m+2
=>x1^2+x2^2-2|x1x2|=m+2
=>(x1+x2)^2-2x1x2-2|x1x2|=m+2
=>(2m)^2-2(-1)-2|-1|=m+2
=>4m^2-m-2=0
=>m=(1+căn 33)/8; m=(1-căn 33)/8
Đúng 0
Bình luận (0)