Question

In an ellipse the distance between the foci is 6 and it’s minor axis is 8. Then its eccentricity is

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

Distance between foci $=6\Rightarrow 2ae=6\Rightarrow ae=3$
Minor axis $=8\Rightarrow b^2=16\Rightarrow a^2(1-e^2)=16\Rightarrow a^2-a^2{e}^2=16\Rightarrow a^2=16+9=25\Rightarrow a=5\Rightarrow a=5\Rightarrow e=\frac{3}{3}$