document.write( "Question 199381: Analytic Geometry
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document.write( "14. Determine the shortest distance from the point H(5,2) tot he line through points J(-6,4) and K(-2,-4)\r
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document.write( "Thank you alot!! \n" );
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Algebra.Com's Answer #149816 by Alan3354(69443)![]() ![]() You can put this solution on YOUR website! Determine the shortest distance from the point H(5,2) tot he line through points J(-6,4) and K(-2,-4) \n" ); document.write( "-------------------- \n" ); document.write( "Method: Find the slope of the line JK. The shortest distance from a point to a line is along a line perpendicular, to JK in this case. The slope of lines perpendicular is the negative inverse of the slope of JK. \n" ); document.write( "------ \n" ); document.write( "Slope, m, of JK = diffy/diffx = (-4-4)/(-2 - (-6)) = -8/4 \n" ); document.write( "m of JK = -2 \n" ); document.write( "------------ \n" ); document.write( "The slope of ALL lines perpendicular to JK have a slope of +1/2 \n" ); document.write( "To find the equation of the line thru H with a slope of +1/2, use \n" ); document.write( "y-y1 = m*(x-x1) \n" ); document.write( "y-2 = (1/2)*(x-5) \n" ); document.write( "2y-4 = x-5 \n" ); document.write( "x-2y = 1 (eqn of line thru H) \n" ); document.write( "------------------------------ \n" ); document.write( "Find the eqn of JK: \n" ); document.write( "Use the same method with either point, J or K \n" ); document.write( "y+4 = -2*(x+2) \n" ); document.write( "y = -2x-8 \n" ); document.write( "------------ \n" ); document.write( "Find where the lines intersect by solving the 2 eqns. \n" ); document.write( "x-2y = 1 (eqn of line thru H) \n" ); document.write( "y = -2x-8 \n" ); document.write( "Sub for y into eqn thru H \n" ); document.write( "x - 2(-2x-8) = 1 \n" ); document.write( "x+4x + 16 = 1 \n" ); document.write( "5x = -15 \n" ); document.write( "x = -3 \n" ); document.write( "------- \n" ); document.write( "y = -2 \n" ); document.write( "--> Intersection at (-3,-2) \n" ); document.write( "------------ \n" ); document.write( "Find distance from H to intersection: \n" ); document.write( "d^2 = (5+3)^2 + (2+2)^2 = 64+16 \n" ); document.write( "distance = sqrt(80) \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |