eccentricity

Question

what is the eccentricity of:

(x+1)^2/4 + (y-5)^2/9 = 1 ?

x^2/9 + y^2/81 = 1 ?

(x+2)^2/36 + (y-4)^2/11 = 1?

Answer 1

All of the given are ellipses.

Eccentricity for an ellipse:

√(a² - b²) / a

 

For the first:

e = √5 / 3

 

Use the same formula for the other two.