Tuesday

September 23, 2014

September 23, 2014

Posted by **Cal** on Sunday, April 19, 2009 at 6:33pm.

(1) 9x^2+4y^2+36x-24y+36=0

(2) Vertices: (0,5)(0,-5)

Passes through the point (4,2)

Centered at the origin

- Pre-Cal -
**Reiny**, Sunday, April 19, 2009 at 7:31pmfor the first one, complete the square :

9x^2+4y^2+36x-24y+36 = 0

9(x^2 + 4x + ____) + 4(y^2 - 6y + ____) = -36

9(x^2 + 4x + 4) + 4(y^2 - 6y + 9) = -36+36+36

9(x+2)^2 + 4(y-3)^2 = 36

divide each term by 36

(x+2)^2/4 + (y-3)^2/9 = 1

for 2. remember that from the vertices we know a = 5

standard form with centre at (0,0) is

x^2/a^2 + y^2/b^2 = 1

so we have

x^2/25 + y^2/b^2 = 1

but (4,2) lies on it, so

16/25 + 4/b^2 = 1

I will leave it up to you to solve for b^2, and plug that back into the above equation.

**Answer this Question**

**Related Questions**

Math - Find the center, vertices, foci, and eccentricity of the ellipse. 9x^2 + ...

Pre-calculus - For the ellipse with equation 5x^2+64y^2+30x+128y-211=0, find the...

College Algebra. - Find the equation in standard form of the ellipse, given ...

pre cal - finding the standard form the center eccentricity vertices foci and ...

Algebra II-Please check my calculation - Find center, vertices, co-vertices and ...

Algebra 2 - Choose the equation that best represents an ellipse for the given ...

Math - Find the center, vertices, foci, and eccentricity of the ellipse. 9x^2 + ...

Pre-calc - Heres the equation: (x^2)-(4y^2)-(4x)+(24y)-(36)=0 Your supposed to ...

pre cal - find the standard form of the equation of a parabola with the vertex (...

precal help - Find a Parabola with Vertex (3,1) Focus (4,1) Find the vertex of ...