Let $f ( x , y ) = x ^ { 2 } + 3 y ^ { 2 } - 3 x$

Multiple Choice

Let $f ( x , y ) = x ^ { 2 } + 3 y ^ { 2 } - 3 x$ Find the gradient vector of f at the point (-1, 2) .

A) $\nabla f = - 5 \vec { i } - 12 \vec { j }$
B) $\nabla f = - 5 \vec { i } + 24 \vec { j }$
C) $\nabla f = 5 \vec { i } + 12 \vec { j }$
D) $\nabla f = - 5 \vec { i } + 12 \vec { j }$