Question

If the distance from a fixed straight line is equal to the distance from a fixed point then what is the value of eccentricity?

(a) Unity

(b) Greater than one

(c) Infinity

(d) Zero

I have been asked this question in my homework.

The above asked question is from Basics of Conic Sections topic in portion Curves used in Engineering Practice of Engineering Drawing

Answer 1

Right choice is (a) Unity

Explanation: The fixed straight line is called as directrix and the fixed point is called as a focus. Eccentricity is defined as the ratio of the distance from the focus to the distance from the directrix and it is denoted by e. Hence from definition e = x ÷ x = 1.