Q12 of 63 Page 202

Given the ellipse with equation 9x2 + 25y2 = 225, find the eccentricity and foci.

Equation of an ellipse = , whereas


Length of latus rectum =


Length of minor axis = 2b


9x2 + 25y2 = 225


Dividing the equation by 225,




a = 5, b = 3


b2 = a2 (1 - e2)


32 = 52 (1 - e2)






Foci = (±ae,0)


=


Hence, the eccentricity is and foci is (±4,0).


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