Find two positive numbers that satisfy the given requirements.(adsbygoogle = window.adsbygoogle || []).push({});

The Product is 192 and the sum is a minimum.

I said that x*y=192 and y=192/x and that dy/dx= -192/x^2

I thought that we were supposed to set the derivitive equal to zero in order to find the local extrema... however -192/x^2 does not equal 0...right???

I'm dazed and confused... can someone please help?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Simple application of Derivitives problem

**Physics Forums | Science Articles, Homework Help, Discussion**