document.write( "Question 1168157: Two ships leave a port O.
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document.write( "One ship travels on a bearing of 340° to a point P which is 50 km from O.
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document.write( "The other ship travels on a bearing of 060° to a point Q, 85 km from O.
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document.write( "(a) draw a diagram to represent the position of the port and the two ships. On your diagram carefully label north, the given angles and the distance travelled.
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document.write( "(b) calculate the distance PQ in km.
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document.write( "(c) Determine the bearing of P from O. \n" );
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Algebra.Com's Answer #792803 by Boreal(15235)![]() ![]() You can put this solution on YOUR website! Draw this \r \n" ); document.write( "\n" ); document.write( "Law of cosines with a being OP and b being OQ, c is PQ. \n" ); document.write( "c^2=a^2+b^2-2abcosC \n" ); document.write( "=50^2+85^2=2(4250)cos 80 \n" ); document.write( "=2500+7225-1476 \n" ); document.write( "=8248.99=8249 \n" ); document.write( "c=sqrt(8249) \n" ); document.write( "=90.82 or 91 km.\r \n" ); document.write( "\n" ); document.write( "law of sines for angle Q \n" ); document.write( "sin 80/90.82=sin x/50 \n" ); document.write( "sin x=0.5421 \n" ); document.write( "take arc sin of that \n" ); document.write( "x=32.83 deg \r \n" ); document.write( "\n" ); document.write( "It can be shown on the drawing that the triangle in the second quadrant has angles 20, 67.17, and therefore 92.83 deg \n" ); document.write( "That means the part of the triangle between the horizontal line at the y-axis to the bearing has to be 2.83 degrees. \n" ); document.write( "The bearing from point Q (I think you meant that and not point O, which would simply bear 340, since it is given) is 270 deg + that 2.83 deg or 272.83 deg.\r \n" ); document.write( "\n" ); document.write( "Alternatively, Point Q is 42.5 km N of point O and point P is 50 sin 70 or 46.98 km north of point O. PQ is the hypotenuse of a triangle with vertical distance 4.5 miles. \n" ); document.write( "sine of the angle is 4.5/90.82, and the angle can be shown to be 2.84 degrees. \n" ); document.write( " |