Question

The sum of a number squared and a number is 27. The product of the two numbers is a maximum. I did this and got +/- sqrt(13.5) but my teacher insists I have a calculation error. Help?

Answer 1

lol. hi.

Answer 2

I don't quite get the question here, are you supposed to find max(xy) with x²y=27 ?

Answer 3

Sigh. I'm supposed to be finding the value of x based on given information.

Answer 4

If I'm not mistaken, the max product would be xy=54 at (x,y)=(3,18)

Answer 5

how do you get x=3?

Answer 6

Because (3.18) is a local maxima of the function xy given x²+y=27

Answer 7

I didn't actually find it manually as it takes too much time, but I used an online tool that can do that?

Answer 8

that.*

Answer 9

thanks for all your help.

Answer 10

Always welcome :3