document.write( "Question 198100: a circle passes through the point (9,3) and has a center (2,27). write the equation. give me a step by step on how to do it \n" ); document.write( "

Algebra.Com's Answer #148568 by josmiceli(19441) $\"\"$ $\"About$

You can put this solution on YOUR website!
The general equation for a circle in xy-plane is:
\n" ); document.write( " $\"%28x+-+x%5B0%5D%29%5E2+%2B+%28y+-+y%5B0%5D%29%5E2+=+r%5E2\"$
\n" ); document.write( " $\"x%5B0%5D\"$ and $\"y%5B0%5D\"$ are coordinates of the center,
\n" ); document.write( "given as (2,27)
\n" ); document.write( " $\"r\"$ is the radius.
\n" ); document.write( "I can plug in (2,27)
\n" ); document.write( " $\"%28x+-+2%29%5E2+%2B+%28y+-+27%29%5E2+=+r%5E2\"$
\n" ); document.write( " $\"x\"$ and $\"y\"$ in the equation are ANY $\"x\"$ and
\n" ); document.write( " $\"y\"$ on the circle, so if I plug in (9,3) , that is a
\n" ); document.write( "valid solution, and I can then solve for $\"r\"$
\n" ); document.write( " $\"%289+-+2%29%5E2+%2B+%283+-+27%29%5E2+=+r%5E2\"$
\n" ); document.write( " $\"7%5E2+%2B+%28-24%29%5E2+=+r%5E2\"$
\n" ); document.write( " $\"49+%2B+576+=+r%5E2\"$
\n" ); document.write( " $\"r%5E2+=+625\"$
\n" ); document.write( " $\"r+=+25\"$
\n" ); document.write( "The equation is:
\n" ); document.write( " $\"%28x+-+2%29%5E2+%2B+%28y+-+27%29%5E2+=+625\"$ \n" ); document.write( "

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