Question

Of all numbers whose difference is 18, find the two that have the minimum product

Answer 1

0 and -18?

Answer 2

Nope, since you can get negative #'s.. hmmm

Answer 3

-9 and 9?

Answer 4

well let the numbers be x and x - 18

so there product is

\[P(x) = x(x -18)....or.....P(x) = x^2 - 18x\]

now find the 1st derivative... and then let it equation 0 and solve for x.

this will be the minimum value....

Answer 5

this isnt the exact question but maybe it will give you helpful steps
http://answers.yahoo.com/question/index?qid=20080314095143AAmHFLp

Answer 6

2x-18=0
x=9,-9