Use Lagrange Multipliers to Find the Maximum Value of F $f \left( \frac { 5 } { 4 } , \frac { 9 } { 4 } \right) = \frac { 405 } { 16 }$

Multiple Choice

Use Lagrange multipliers to find the maximum value of f (x, y) = 9xy subject to the constraint 9x + 5y = 45.

A)
$f \left( \frac { 5 } { 4 } , \frac { 9 } { 4 } \right) = \frac { 405 } { 16 }$
B)
$f \left( \frac { 5 } { 2 } , \frac { 9 } { 2 } \right) = \frac { 405 } { 4 }$

C) f (5, 9) = 405

D) f (0, 0) = 0