Two ordinary questions from calculas3, I want an expert to send me the answer urgently, important and necessary

x2 +1 /y-2y lim (x,y) +(4,16) I- Vy 6 0 does not exist O 15 0 12 0 OO SHOT ON REDMI 7 AI DUAL CAMERAThe level curves of the function are f (x, y) = Va2 - y2 - 1 lines O parabolas O hyperbolas O ellipses O circles OO SHOT ON REDMI 7 AI DUAL CAMERA