Question

What are the foci of the ellipse given by the equation 25x^2 + 16y^2= 400?


(± 3, 0)
(± 3, 0)

(± 9, 0)
(± 9, 0)

(0, ± 3)
(0, ± 3)

(0, ± 9)

Answers

GPT 3.5
The standard form equation of an ellipse is (x-h)^2/a^2 + (y-k)^2/b^2 = 1, where (h,k) is the center of the ellipse, a is the distance from the center to a vertex along the x-axis, and b is the distance from the center to a vertex along the y-axis.

Given the equation 25x^2 + 16y^2 = 400, we can rewrite it as (x^2/16) + (y^2/25) = 1 by dividing by 400 on both sides.

Comparing with the standard form equation, we see that a = 4 and b = 5. The center is at (0,0).

For an ellipse, the foci are given by the formula c^2 = a^2 - b^2. In this case c^2 = 16 - 25 = -9. Taking the absolute value, we find that c = 3.

Therefore, the foci are given by (± 3, 0).