document.write( "Question 260136: 4x^2+4y^2= 81
\n" ); document.write( "determine the center and radius of the circle \n" ); document.write( "

Algebra.Com's Answer #191584 by Earlsdon(6294) $\"\"$ $\"About$

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Given:
\n" ); document.write( " $\"4x%5E2%2B4y%5E2+=+81\"$ determine the center and the radius.
\n" ); document.write( "Let's first get your equation into the standard form for a circle:
\n" ); document.write( " $\"%28x-h%29%5E2%2B%28y-k%29%5E2+=+r%5E2\"$ where the center is at (h, k) and the radius is r.
\n" ); document.write( " $\"4x%5E2%2B4y%5E2+=+81\"$ Divide both sides by 4.
\n" ); document.write( " $\"x%5E2%2By%5E2+=+20.25\"$ This is now in standard form, so h = 0, k = 0, and $\"r%5E2+=+20.25\"$ and $\"r+=+4.5\"$
\n" ); document.write( "The center is at (0, 0) and the radius is r = 4.5 \n" ); document.write( "

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