Let $z = 2 x ^ { 2 } + x y - y ^ { 2 }$

Multiple Choice

Let $z = 2 x ^ { 2 } + x y - y ^ { 2 }$ . Then the change of z from (2, -1) to (2.1, -1.1) approximated by $d z$ is

A) 1.32
B) 0.94
C) 0.77
D) 0.58
E) 0.3