Use the Linearization $L ( x , y )$ Of the Function

Short Answer

Use the linearization $L ( x , y )$ of the function.
$f ( x , y ) = \sqrt { 9 - x ^ { 2 } - 2 y ^ { 2 } }$ at $( - 1,1 )$ to approximate $f ( - 0.93,0.75 )$ .