Need help with these 3 questions !

Use polar coordinates to find the limit. [If (r, 0) are polar coordinates of the point (x, y) with / 2 0, note that r - 0.+ as (x, y) - (0, 0).] (If an answer does not exist, enter DNE.) ( x, y ) - (0, 0) ( x 2 + y 2 ) In ( x 2 + y?) Need Help? Read It 19. [-/1 Points] DETAILS SCALC9 14.2.502.XP. 0/15 Submissions Used MY NOTES ASK YOU Find the limit, if it exists. (If an answer does not exist, enter DNE.) (x, y) - (3, -3) "cos ( x + y) Need Help? Read It 20. [-/1 Points] DETAILS SCALC9 14.2.506.XP. 0/15 Submissions Used MY NOTES ASK YOU Find the limit, if it exists. (If an answer does not exist, enter DNE.) x2yey lim ( x, y) - (0, 0) x4 + 6y2