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5.2. (f)
Answers to Exercises and Solutions to Problems1 +r+r2-15 +-15 -5
5.3. (b) The quadratic has a single zero of multiplicity 2. If the quadratic
has two distinct zeros on the curve 1~1 = 1, the image Di of this curve
would pass through the origin twice and therefore have a double loop. For
T close to 1, D, would also display the double loop, and the loop would
disappear for some value of r strictly less than 1. In the present case, the
double loop occurs when r > 1, but disappears precisely at the point when
it passes through the origin.