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MC III Algebra Help

 
 
SongKevin的头像
MC III Algebra Help
SongKevin - 2022年07月19日 Tuesday 17:34
 

Hi,

For 3.21, I calculated the determinant, 

\( \Delta = (2(m+1))^2 - 4*1*(3m^2+4mn+4n^2+1) = 2m^2-2m+4mn+4n^2+1 \geq 0 \)

I simplified to \( (m-1)^2+(m+2n)^2 \geq 0 \)

but I don't know where to go from there since that doesn't tell you anything.

 
WangDr. Kevin的头像
Re: MC III Algebra Help
WangDr. Kevin - 2022年07月20日 Wednesday 12:55
 

Are you sure your discriminant is simplified correctly?  You canceled a negative number, and that reverses the direction of the inequality.