Find an equation of the ellipse and graph it Center at 1 2 F
Find an equation of the ellipse and graph it. Center at (1, 2); Focus at (1, 4); contains the point (2, 2)
Solution
centre ( 1,2)
focus ( 1,4)
point ( 2,2)
standrad equation of ellipse is
(y-k)^2/a^2 + ( x-h)^2/b^2 = 1
where , h , k = centre
distance between foci and centre = c = 2 units
hence , c^2 = a^2 - b^2
2^2 = a^2 - b^2
4 = a^2 - b^2 ---------------- equation 1
from standard equation
(y-k)^2/a^2 + ( x-h)^2/b^2 = 1
plugging the centre and a point in the equation
(2-2)^2/a^2 + (2-1)^2 / b^2 = 1
b^2=1
a^2 = 5 ( from equation 1)
hence, equation of ellipse is
(y-2)^2 / 5 + (x-1)^2/ 1 = 1
