# Math Help - Is the eccentricity of this ellipse correct?

1. ## Is the eccentricity of this ellipse correct?

eccentricity = sqrt(a^2 - b^2)/a (I think this formula is correct for the following ellipse) THANKS WILL BE GIVEN TO THOSE WHO HELP!

[(x^2) / 25] +[(y-3)^2 / 9] = 1

e = SQRT(25^2 - 9^2)/25

e = SQRT( 625 - 81)/25

e = 23.32/ 25

e = .9328

Thanks

2. Originally Posted by bobbyboy1111
eccentricity = sqrt(a^2 - b^2)/a (I think this formula is correct for the following ellipse) THANKS WILL BE GIVEN TO THOSE WHO HELP!

[(x^2) / 25] +[(y-3)^2 / 9] = 1

e = SQRT(25^2 - 9^2)/25

e = SQRT( 625 - 81)/25

e = 23.32/ 25

e = .9328
No, you have squared the numbers twice. If the equation is $\frac{x^2}{5^2} + \frac{(y-3)^2}{3^2} = 1$ then a=5, b=3 and $e^2 = (5^2-3^2)/5^2 = 16/25$, so e=4/5.