# The all popular minimization problem

• Nov 6th 2007, 12:42 PM
pseizure2000
The all popular minimization problem
A rectangle has area 4 sq. cm. A straight line is to be drawn from one corner of the rectangle to the midpoint of one of the two more distant sides. What is the minimum possible length of such a line?

How does one calculate this? I've tried doing it several ways and still can't seem to get the correct answer.
• Nov 6th 2007, 03:35 PM
pseizure2000
the farthest i can get is $Length =sqrt (x^2 + (2/x)^2)$
• Nov 6th 2007, 03:44 PM
Jhevon
Quote:

Originally Posted by pseizure2000
the farthest i can get is $Length =sqrt (x^2 + (2/x)^2)$

that is correct so far. now find the derivative (by the chain rule) and set it to zero and solve for x. and you can find the minimum z.