$x = r \cos \theta$ And $y = r \sin \theta$

Multiple Choice

$$\text { Use polar coordinates to find the limit } \lim _ { ( x , y ) \rightarrow ( 0,0 ) } 2 \cos \left( x ^ { 2 } + y ^ { 2 } \right) \text {. [Hint: Let }$$ $x = r \cos \theta$ and $y = r \sin \theta$ , and note that $( x , y ) \rightarrow ( 0,0 )$ implies $r \rightarrow 0 . ]$

A) $\frac { \sqrt { 3 } } { 2 }$
B) 0
C) $\frac { 1 } { 2 }$
D) 2
E) $\frac { \sqrt { 2 } } { 2 }$