Math Prob 27?

Question

Whats the foci?

5x^2 + 9y^2 = 45

Answer 1

5x^2 + 9y^2 = 45
x²/9 + y²/5 = 1

The center of the ellipse is (0,0). It is a horizontal ellipse so the foci are at (-c,0) and (c,0).

c² = a² - b² = 9 - 5 = 4
c = 2

So the foci are at (-2,0) and (2,0).