Let $f ( x , y ) = \frac { 1 } { x } - \frac { 64 } { y } + x y$ . Then f has a relative maximum at

A) $\left( - \frac { 1 } { 4 } , 16 \right)$
B) $\left( \frac { 1 } { 4 } , 16 \right)$
C) $\left( \frac { 1 } { 4 } , 32 \right)$
D) $\left( - \frac { 1 } { 4 } , - 16 \right)$
E) $\left( \frac { 1 } { 4 } , - 16 \right)$

Question

Let $f ( x , y ) = \frac { 1 } { x } - \frac { 64 } { y } + x y$ . Then f has a relative maximum at

A) $\left( - \frac { 1 } { 4 } , 16 \right)$
B) $\left( \frac { 1 } { 4 } , 16 \right)$
C) $\left( \frac { 1 } { 4 } , 32 \right)$
D) $\left( - \frac { 1 } { 4 } , - 16 \right)$
E) $\left( \frac { 1 } { 4 } , - 16 \right)$

Quizplus · Accepted Answer

The Answer of Let $f ( x , y ) = \frac { 1 } { x } - \frac { 64 } { y } + x y$ . Then f has a relative maximum at

A) $\left( - \frac { 1 } { 4 } , 16 \right)$
B) $\left( \frac { 1 } { 4 } , 16 \right)$
C) $\left( \frac { 1 } { 4 } , 32 \right)$
D) $\left( - \frac { 1 } { 4 } , - 16 \right)$
E) $\left( \frac { 1 } { 4 } , - 16 \right)$

Let f(x,y)=1x−64y+xyf ( x , y ) = \frac { 1 } { x } - \frac { 64 } { y } + x yf(x,y)=x1​−y64​+xy

Let $f ( x , y ) = \frac { 1 } { x } - \frac { 64 } { y } + x y$