Use Lagrange Multipliers to Solve the Problem $f ( x , y ) = x y$

question 44

Multiple Choice

Use Lagrange Multipliers to solve the problem.
Find the maximum value of $f ( x , y ) = x y$ subject to $x + 2 y = 80$ .

• A) \(f _ { \max } = 800\)
• B) \(f _ { \max } = 40\)
• C) \(f _ { \max } = 400\)
• D) \(f _ { \max } = 2\)
• E) \(f _ { \max } = 10\)