Knock out the true statements

Exercise and reference answers

Questions

1. Question

   Eliminate the true statements about conics.

   Choices

   1. Item

      A parabola cuts across both nappes

      Correct

      Yes

   2. Explanation

      That intersection is what defines a conic section.

      Item

      A conic is a plane cutting a cone

   3. Explanation

      The sum of the distances to the two foci is constant.

      Item

      An ellipse keeps the sum fixed

   4. Explanation

      The two parts either side of the vertex are the nappes.

      Item

      The vertex divides a cone into two nappes

Instructions

Remove the statements that are true. One false one should survive.

Explanation