Need help finding values in an multivariable function

[jn182]

Hello,

Having some problem on how to start on this problem:

For which values of r has the equation x^2+xy+y^2+r = sqrt(1-x^2-y^2) at least on solution (x,y)?


Thanks,
Johan

 

[stapel]

Having some problem on how to start on this problem:

For which values of r has the equation x^2+xy+y^2+r = sqrt(1-x^2-y^2) at least on solution (x,y)?

One way to start might be to square both sides, and see where that leads. What do you get? What are your thoughts?

 

[jn182]

Finally figured it out. Just put the r as a function f(x,y) and then it was just to find the extreme values. :cool:
Thanks