Question 1
Express the area A of the cross-section of the ellipsoid x
2 +

+

= 1 in the plane z = c as a function of c where -3 ≤ c ≤ 3. (The area of an ellipse with semi-axes a and b is πab.)
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square units
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square units
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square units
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square units
Question 2
Find two one-parameter families of straight lines that lie on the hyperbolic paraboloid z = xy.