document.write( "Question 617271: A cruise ship sailed north for 50 km. Then, the captain turned the ship eastward through an angle of pi/6 and sailed an additional 50 km. Without using a calculator, determine an exact expression for the direct distance from the start to the finish of the cruise. \n" ); document.write( "
Algebra.Com's Answer #388242 by nerdybill(7384)\"\" \"About 
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A cruise ship sailed north for 50 km. Then, the captain turned the ship eastward through an angle of pi/6 and sailed an additional 50 km. Without using a calculator, determine an exact expression for the direct distance from the start to the finish of the cruise.
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\n" ); document.write( "π/6 = 30 deg = turn from north towards the east.
\n" ); document.write( "supplementary angle (inside triangle formed) = (180 - 30) = 150 deg
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\n" ); document.write( "This forms a 50 Km, 50 Km, side_c triangle with the angle between the
\n" ); document.write( "two 50 Km sides = 150 deg.
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\n" ); document.write( "use the law of cosines: where C = 150 deg
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\n" ); document.write( "c² = a² + b² − 2abcos[C]
\n" ); document.write( "c² = (50)² + (50)² − 2(50)(50)cos[150] ... cos[150] = (-√3)/2
\n" ); document.write( "c² = 5000 + 2500(√3)\r
\n" ); document.write( "\n" ); document.write( "\"c%5E2+=+a%5E2+%2B+b%5E2+-+2ab%2Acos%28C%29\"
\n" ); document.write( "\"c%5E2+=+50%5E2+%2B+50%5E2+-+2%2A50%2A50%2Acos%28pi%2F6%29\"
\n" ); document.write( "\"c%5E2+=+2500+%2B+2500+-+100%2A50%2A%28-sqrt%283%29%2F2%29\"
\n" ); document.write( "\"c%5E2+=+5000+-+5000%2A%28-sqrt%283%29%2F2%29\"
\n" ); document.write( "\"c%5E2+=+5000+%2B+5000%2A%28sqrt%283%29%2F2%29\"
\n" ); document.write( "\"c%5E2+=+5000+%2B+2500%2Asqrt%283%29\"
\n" ); document.write( "\"c+=+sqrt%285000+%2B+2500%2Asqrt%283%29%29\"\r
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