A water line is to be built from point to point and must
Chapter 13, Problem 81(choose chapter or problem)
A water line is to be built from point P to point S and must pass through regions where construction costs differ (see figure). The cost per kilometer in dollars is 3k from P to Q, 2k from Q to R, and k from R to S. For simplicity, let k = 1. Use Lagrange multipliers to find x, y, and z such that the total cost C will be minimized.
Unfortunately, we don't have that question answered yet. But you can get it answered in just 5 hours by Logging in or Becoming a subscriber.
Becoming a subscriber
Or look for another answer