Let x and y be real numbers such that xy=9 Find the set of all possible values of x+y

Guest May 24, 2021

#1**0 **

I think since sqrt(9) = +- 3, it can be all numbers other than -6 to 6 (non inclusive)

=^._.^=

catmg May 24, 2021

#2**+1 **

Use AM-GM for positive x,y, we can get that x+y>=6, and for negatives x+y<=-6.

So, it is either x+y>=6 or x+y<=-6.

ilovepizza547 May 24, 2021