Question

20. What is the eccentricity of the ellipse whose equation is [(x²) / 25] +[(y-3)² / 9] = 1

Answer 1

x²/25+(y-3)²/9=1.

The distance c of either focus from the ellipse’s origin (at (0,3)) is given by:

c²=25-9=16, so c=√16=4.

Eccentricity, e=c/a where a is the length of the semi major axis, which in this case is √25=5. So e=4/5=0.8.