Posted by **MATHLETE** on Wednesday, May 4, 2011 at 10:37pm.

Find the foci for the equation of an ellipse:

2x^2 + 8x + y^2 + 4 = 0

- math -
**drwls**, Wednesday, May 4, 2011 at 10:58pm
2(x^2 + 4x + 4) + y^2 = -4 + 8 = 4

2(x+2)^2 + y^2 = 4

(x+2)^2/2 + y^2/4 = 1

[(x+2)/sqrt2]^2 + (y/2)^2 = 1

The ellipse center is at(-2, 0)

The semiminor axis length is sqrt2

The semimajor axis length is 2

The foci along the vertical axis at x = -2, at +/- c, where c = sqrt (4 - 2) = sqrt2

## Answer this Question

## Related Questions

- Algebra - 1. What is the equation an ellipse with foci at (0, ±2 √10 ) and...
- maths - Given that the ellipse x^2/a^2 + y^2/b^2 =1 has foci at(+/-ae,0)where e ...
- Math - Find an equation for the ellipse. center:(3,2) a=3c Foci:(1,2)(5,2) h=3 k...
- pre-calculus - the foci of an ellipse are (0,2) (0,-2) and the eccentricity is 1...
- Math/Conics - Find the center, vertices, and foci of the ellipse with the ...
- Algebra 2 - Choose the equation that best represents an ellipse for the given ...
- Pre-calculus - For the ellipse with equation 5x^2+64y^2+30x+128y-211=0, find the...
- Math/Algebra - Find the standard equation of an ellipse with the given ...
- AlgebraII - Choose the equation that best represents an ellipse for the given ...
- algebra - Choose the equation that best represents an ellipse for the given foci...