# Math Help - find equation of ellipse

1. ## find equation of ellipse

with minor vertices (-3,4) and (1,4) and eccentricity=4/5

book says answer is

{(x+1)^2}/4 + {(y-4)^2/100/9}=1

buy i cannot get this answer????? HELP!!!!!

2. ## Re: find equation of ellipse

Originally Posted by sluggerbroth
with minor vertices (-3,4) and (1,4) and eccentricity=4/5
book says answer is{(x+1)^2}/4 + {(y-4)^2/100/9}=1
You should know that $\dfrac{(x-h)^2}{a^2}+\dfrac{(y-k)^2}{b^2}=1$.
Where $(h,k)$ is the midpoint of the axis.
Here $a=2$. WHY?
Using the eccentricity, how do you $b~?$