document.write( "Question 1129367: A circle touches the x axis at the point P(-3,0) and its center C lies on the line 2x+y+1=0. Find:
\n" ); document.write( "(a)coordinates of C
\n" ); document.write( "(b)radius of the circle
\n" ); document.write( "(c)equation of the circle
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Algebra.Com's Answer #745926 by MathLover1(20849)\"\" \"About 
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Find:
\n" ); document.write( "(a) coordinates of C \r
\n" ); document.write( "\n" ); document.write( " center C (\"h\",\"k\") lies on a intersection of the line \"2x%2By%2B1=0\" is perpendicular to the given line that passes through the point P(\"-3\",\"0\")\r
\n" ); document.write( "\n" ); document.write( "find a tangent line \r
\n" ); document.write( "\n" ); document.write( "\"2x%2By%2B1=0\".........find slope
\n" ); document.write( "\"y=-2x-1\".....eq.1-> \"m=-2\"\r
\n" ); document.write( "\n" ); document.write( "the line perpendicular to a given line will have a slope \"-1%2Fm=-1%2F-2=1%2F2\"
\n" ); document.write( "equation is:\r
\n" ); document.write( "\n" ); document.write( "\"y-0=%281%2F2%29%28x-%28-3%29%29\"\r
\n" ); document.write( "\n" ); document.write( "\"y=%281%2F2%29%28x%2B3%29\"\r
\n" ); document.write( "\n" ); document.write( "\"y=%281%2F2%29x%2B3%2F2\".....eq.2\r
\n" ); document.write( "\n" ); document.write( "find intersection of these two lines:
\n" ); document.write( "\"%281%2F2%29x%2B3%2F2=-2x-1\"
\n" ); document.write( "\"%281%2F2%29x%2B2x=-3%2F2-1\"
\n" ); document.write( "\"%285%2F2%29x=-5%2F2\"
\n" ); document.write( "\"x=-1\"
\n" ); document.write( "\"y=-2%28-1%29-1\".....eq.1-> \"y=1\"\r
\n" ); document.write( "\n" ); document.write( "intersection point: (\"-1\",\"1\")\r
\n" ); document.write( "\n" ); document.write( "so,C (\"h\",\"k\") = C(\"-1\",\"1\") \r
\n" ); document.write( "\n" ); document.write( "(b)radius of the circle \r
\n" ); document.write( "\n" ); document.write( "distance from C (\"-1\",\"1\") to P(\"-3\",\"0\")\r
\n" ); document.write( "\n" ); document.write( "\"r=sqrt%28%28-1-%28-3%29%29%5E2%2B%281-0%29%5E2%29\"
\n" ); document.write( "\"r=sqrt%284%2B1%29\"
\n" ); document.write( "\"r%5E2=5\"\r
\n" ); document.write( "\n" ); document.write( "(c)equation of the circle \r
\n" ); document.write( "\n" ); document.write( "\"%28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"%28x%2B1%29%5E2%2B%28y-1%29%5E2=5\"\r
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