Question

The locus of a point which moves such that the difference of its distances from two fixed points is always a constant is

• A. A straight line
• B. A circle
• C. An ellipse
• D. A hyperbola

Answer 1

The correct option is C An ellipse

Let $S$ and $S^{\prime }$ be the two fixed points and $P$ be some arbitrary point.

Given that $|SP-S^{\prime }P|=constant$

The above equation satisfy for any equation of hyperbola with $S$ and $S^{\prime }$ as its foci