Question

How to find two positive x and y that minimize Q=x^2y if x+y+2 ?

Answer 1

did u mean x+y=2?

Answer 2

oh, yes, sorry x+y=2

Answer 3

x+y = 2
y = 2-x
Q=(x^2)*y = x^2(2-x) = 2x^2-x^3
Q' = 4x - 3x^2 = 0
x(4-3x)=0
x=0;
4-3x=0, -3x=-4; x=4/3

Answer 4

@S did you leave? Because it looks like @Brutal was putting in some time to help you here...

Answer 5

no , i am steel here, just trying to understand this

Answer 6

still*

Answer 7

Cool, no worries then - as you were ;)

Answer 8

okay just keep the positive positive value: x=4/3
x=4/3, but you know that y = 2- x, so y = 2-(4/3) = (6-4)/3 = 2/3

Answer 9

yes, was just thinking about y value =D, thank you soo much for your help!

Answer 10

Great job both of you @S and @Brutal. Thank you from OpenStudy!

Answer 11

np :)