document.write( "Question 1135183: A ship is anchored off a long straight shoreline that runs north and south. From two observation points 19 miles apart on shore, the bearings of the ship are N 36° E and S 56° E. What is the shortest distance from the ship to the shore? (Round your answer to the nearest tenth.)
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document.write( "= mi \n" );
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Algebra.Com's Answer #752838 by Theo(13342)![]() ![]() You can put this solution on YOUR website! the ship and the two shore points form a triangle.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "A is the north point on the shore. \n" ); document.write( "B is the ship. \n" ); document.write( "C is the south point on the shore. \n" ); document.write( "angle A is 56 degrees. \n" ); document.write( "angle C is 36 degrees. \n" ); document.write( "draw a line from point B perpendicular to the line AC and connecting to line AC at point D. \n" ); document.write( "line BD is the shortest distance to the shore.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "the length of the line AC is 19. \n" ); document.write( "let the length of the line AD be equal to x and the length of the line DC be equal to 19 - x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "let the length of the line BD be equal to h .\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "two right triangles are formed with a common line of BD.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "these are two right triangles.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "tan(56) = h / x\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "tan(36) = h / (19 - x)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for h in both equation to get:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "h = x * tan(56). \n" ); document.write( "h = (19 - x) * tan(36).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since they're both equal to h, then:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x * tan(56) = (19 - x) * tan(36)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "simplify to get x * tan(56) = 19 * tan(36) - x * tan(36).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "add x * tan(36) to both sides of this equation to get x * tan(56) + x * tan(36) = 19 * tan(36).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "factor out the x to get x * (tan(56) + tan(36)) = 19 * tan(36).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "divide both sides of this equation by (tan(56) + tan(36)) to get x = 19 * tan(36) / (tan(56) + tan(36)).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for x to get x = 6.248828112.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "that makes 19 - x equal to 12.75117189.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in triangle ABD, you get tan(56) = h / x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for h to get h = x * tan(56) which becomes h = 6.248828112 * tan(56) which makes h = 9.264268658.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "in triangle CBD, you get tan(36) = h / (19 - x).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "solve for h to get h = (19 - x) * tan(36) which becomes h = 12.75117189 * tan(36) which makes h = 9.264268658.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "this confirms that h = 9.264268658 miles which is the shortest distance to land.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "here's my diagram of the situation as i see it.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " ![]() \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |