Site icon Noon Academy

Find the equation of the ellipse in the following cases: (i) eccentricity e = ½ and foci (± 2, 0) (ii) eccentricity e = 2/3 and length of latus – rectum = 5

(i) 

   

and

   

Given:

Eccentricity

   

   

Now let us find the equation to the ellipse.

We know that the equation of the ellipse whose axes are x and y – axis is given as

By using the formula,

Eccentricity:

   

It is given that foci

   

Where,

   

   

Or,

   

   

We know

   

   

So,

   

So the equation of the ellipse can be given as

   

∴ The equation of the ellipse is

   

(ii) eccentricity

   

and length of latus rectum

   

Given:

Eccentricity

   

Length of latus – rectum

   

Now let us find the equation to the ellipse.

We know that the equation of the ellipse whose axes are x and y – axis is given as

By using the formula,

Eccentricity:

By using the formula, length of the latus rectum is

   

So the equation of the ellipse can be given as

   

∴ The equation of the ellipse is