# system max

Posers and Puzzles 10 Feb '04 12:38
1. 10 Feb '04 12:38
given:
y&lt;-3(X-4)+5
y&gt;0
and
A=X^2+Y^2
find the largest possible value of A.
2. TheMaster37
Kupikupopo!
10 Feb '04 13:22
given:
y<-3(X-4)+5
y>0
and
A=X^2+Y^2
find the largest possible value of A.
289/10
3. 11 Feb '04 03:42
given:
y<-3(X-4)+5
y>0
and
A=X^2+Y^2
find the largest possible value of A.
i am not sure that this makes sense as written.
if y &lt; -3(x-4) +5, y will be positive for any x &lt; 17/3.
since x can be arbitrarily large negative and satisfy the conditions, A has no maximum.
4. 12 Feb '04 16:24
Originally posted by BarefootChessPlayer
i am not sure that this makes sense as written.
if y < -3(x-4) +5, y will be positive for any x < 17/3.
since x can be arbitrarily large negative and satisfy the conditions, [b]A has no maximum
.
[/b]

the point of this thread is that i to see if anyone knows how to find the maximum of nonlinear systems of inequalities.
5. 12 Feb '04 22:442 edits

the point of this thread is that i to see if anyone knows how to find the maximum of nonlinear systems of inequalities.
did you mean &quot;y&lt;= 3x^4=5&quot;?
the equation you gave has no real solutions. if you accept the above, the possible values for x are: (5/3)^0.25, its negative, and those times i.
if that's the case, any y less than (5/3)^0.25 would be adequate, and thus you'd have no maximum for A again since now y can go large negative.
hope we can solve this one!
6. 18 Feb '04 18:17
Originally posted by BarefootChessPlayer
did you mean "y<= 3x^4=5"?
the equation you gave has no real solutions. if you accept the above, the possible values for x are: (5/3)^0.25, its negative, and those times i.
if that's the case, any y less than (5/3)^0.25 would be adequate, and thus you'd have no maximum for A again since now [b]y
can go large negative.
hope we can solve this one![/b]
oops! i missed that y must be positive.
now maybe i can come up with a solution.
sorry!