document.write( "Question 517509: Find the coordinates of all points that are on the line x=y and are five units from (3,-1). \n" ); document.write( "
Algebra.Com's Answer #344828 by Alan3354(69443)\"\" \"About 
You can put this solution on YOUR website!
Find the coordinates of all points that are on the line x=y and are five units from (3,-1).
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\n" ); document.write( "It's the 2 points of intersection of the line and a circle of radius 5 centered at (3,-1).
\n" ); document.write( "The circle is \"%28x-3%29%5E2+%2B+%28y%2B1%29%5E2+=+25\"
\n" ); document.write( "x = y
\n" ); document.write( "\"%28x-3%29%5E2+%2B+%28x%2B1%29%5E2+=+25\"
\n" ); document.write( "\"2x%5E2+-+4x+-+15+=+0\"
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Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"2x%5E2%2B-4x%2B-15+=+0\") has the following solutons:
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\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
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\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
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\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%28-4%29%5E2-4%2A2%2A-15=136\".
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\n" ); document.write( " Discriminant d=136 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28--4%2B-sqrt%28+136+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%28-4%29%2Bsqrt%28+136+%29%29%2F2%5C2+=+3.91547594742265\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%28-4%29-sqrt%28+136+%29%29%2F2%5C2+=+-1.91547594742265\"
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\n" ); document.write( " Quadratic expression \"2x%5E2%2B-4x%2B-15\" can be factored:
\n" ); document.write( " \"2x%5E2%2B-4x%2B-15+=+%28x-3.91547594742265%29%2A%28x--1.91547594742265%29\"
\n" ); document.write( " Again, the answer is: 3.91547594742265, -1.91547594742265.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B-4%2Ax%2B-15+%29\"

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\n" ); document.write( "x,y = 1 + sqrt(8.5)
\n" ); document.write( "x,y = 1 - sqrt(8.5)
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