document.write( "Question 949013: Identify the center, vertices, co-vertices, foci, length of the major axis, length of the minor axis, and eccentricity of:
\n" );
document.write( "X squared + 9y squared + 8x + 108y +331= 0 \n" );
document.write( "
Algebra.Com's Answer #579298 by lwsshak3(11628)![]() ![]() ![]() You can put this solution on YOUR website! Identify the center, vertices, co-vertices, foci, length of the major axis, length of the minor axis, and eccentricity of: \n" ); document.write( "X squared + 9y squared + 8x + 108y +331= 0 \n" ); document.write( "*** \n" ); document.write( "x^2+9y^2+8x+108y+331=0 \n" ); document.write( "x^2+8x+9y^2+108y=-331 \n" ); document.write( "complete the square: \n" ); document.write( "(x^2+8x+16)+9(y^2+12y+36)=-331+16+324 \n" ); document.write( "(x+4)^2+9(y+6)^2=9 \n" ); document.write( " \n" ); document.write( "This is an equation of an ellipse with horizontal major axis \n" ); document.write( "Its standard form of equation: \n" ); document.write( "center: (-4,-6) \n" ); document.write( "a^2=9 \n" ); document.write( "a=√9=3 \n" ); document.write( "length of major axis=2a=6 \n" ); document.write( "b^2=1 \n" ); document.write( "b=1 \n" ); document.write( "length of minor axis=2b=2 \n" ); document.write( "vertices: (-4±a,-6)=(-4±3,-6)=(-7,-6) and (-1,-6) \n" ); document.write( "co-vertices: (-4-6±b)=(-4,-6±1)=(-4,-7) and (-4,-5) \n" ); document.write( ".. \n" ); document.write( "c^2=a^2-b^2=9-1=8 \n" ); document.write( "c=√8≈2.8 \n" ); document.write( "foci: (-4±c,-6)=(-4±2.8,-6)=(-6.8,-6) and (-1.2,-6) \n" ); document.write( "eccentricity=c/a=√8/3≈0.94 \n" ); document.write( "see graph below: \n" ); document.write( " |