document.write( "Question 1012679: Consider the circle and a secant line y=x. Determine the length of the corresponding secant segment. \n" );
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Algebra.Com's Answer #628682 by Theo(13342) You can put this solution on YOUR website! you have two equations that need to be solved simultaneously.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the solution will be common to both equations.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the equations are:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x^2 + y^2 - 6x - 8y + 9 = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "y = x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "replace y with x in the first equataion to get x^2 + x^2 - 6x - 8x + 9 = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "combine like terms to get 2x^2 - 14x + 9 = 0\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve this quadratic equation to get x = .71612 or x = 6.28388 rounded to 5 decimal places.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since y = x, the coordinate points are (.71612,.71612) or (6.28388,6.28388).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "these points are the points of intersection between the circle and the secant line.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the formula for the length of that secant line is L = sqrt((x2-x1)^2 + (y2-y1)^2).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that becomes L = sqrt((6.28388-.71612)^2 + (6.28388-.71612)^2).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this results in L = 7.874 rounded to 3 decimal places.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "you can also find the intersection points by graphing as shown below.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |