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{\bf Math 225 : Quiz\hfill Oct 2, 1991}

Show your work on a blank sheet of paper with your name and date at the top
(no torn edges).  Circle your final answer. You may use a calculator.

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1. Describe in detail the level curves of
$$f(x,y) = \ln(x^2 + y^2 - 6x - 4y + 22)$$
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2. Calculate the limit
$$\lim_{(x,y)\to(0,0)} {x^2 \over x^2 + y^4}$$
(or show it does not exist).

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