Q2 [25 pts]: Justify your answers clearly. a) [9 pts] Show that limit does not exist (x+7)y lim (x,y)=(-7,0) (x+7)² + y² b) [7 pts] Is the function f(x,y) = (x+7)y (x+7)²+y2 continuous at the point (-7,0)? Justify your answer. If not, find a point that f(x, y) is continuous. c) [9 pts] Determine the set of points at which the function f(x, y) = 7x+3y sinx+7 is continuous.