This function $is$ given $by$

$f(x,y)=\{\begin{array}{ccc}\frac{7xy}{x^2+y^2},& (x,y)(0,& 0)\\ 0,& (x,y)=(0,& 0)\end{array}$

$(a)$ Find a formula for the single variable function $f(0,y).$

$f(0,y)=$

What $isf(0,0)$ for this function?

$f(0,0)=$

Find its $limitasy0$ :

$\underset{y0}{lim}f(0,y)=$

$(b)$ Based $on$ your work $in(a),is$ the single variable function $f(0,y)$ continuous?

$(c)$ Next, similarly consider $f(x,0).$