Use Lagrange multipliers to find the maximum and minimum values of f(x, y)=x+4y subject to the constraint x2+y2=9, if such values exist. Round your answers to three decimal places. If there is no global maximum or global minimum, enter NA in the appropriate answer area. Maximum =

The Lagrangian is

with critical points where the partial derivatives vanish.

Substitute into the last equation and solve for :

Then we get two critical points,

We get an absolute maximum of at the second point, and an absolute minimum of at the first point.

to determine the unit cost your would divide the total cost by the number sold.

7 bagels for $4.41       $4.41/7 = $.63 each at fresh side

5 bagels for $3.60         $3.60/5 = $.72 each at value mart