document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1107840>Question 1107840</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Two boats left the harbour at the same time. One travelled at 10km/h on a bearing pf N47'E. The other travelled at 8km/h on a bearing of N79'E. How far apart were the boats after 45 min? Round your answer to the nearest tenth of a kilometre. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #722891 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=722891\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Two boats left the harbour at the same time.<BR>\n" );
document.write( " One travelled at 10km/h on a bearing pf N47'E.<BR>\n" );
document.write( " The other travelled at 8km/h on a bearing of N79'E.<BR>\n" );
document.write( " How far apart were the boats after 45 min?<BR>\n" );
document.write( " Round your answer to the nearest tenth of a kilometre.<BR>\n" );
document.write( ":<BR>\n" );
document.write( "the angle between the paths of the two boats: 79 - 47 = 32 degrees<BR>\n" );
document.write( "find how far each boat has traveled in 45 min (<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F4 ALIGN=MIDDLE  ALT=\"3%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr)<BR>\n" );
document.write( "Boat l:<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F4 ALIGN=MIDDLE  ALT=\"3%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > * 10 = 7.5 km <BR>\n" );
document.write( "Boat 2: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=3%2F4 ALIGN=MIDDLE  ALT=\"3%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" > * 8 = 6 km<BR>\n" );
document.write( "Use the law of cosines a^2  = b^2 + c^2 - 2(b*c)*cos(A) where<BR>\n" );
document.write( "a = distance between the boats after 45 min<BR>\n" );
document.write( "b = 7.5 km<BR>\n" );
document.write( "c = 6 km<BR>\n" );
document.write( "A = 32 degrees<BR>\n" );
document.write( "a^2 = 7.5^2 + 6^2 - 2(7.5*6)*cos(32)<BR>\n" );
document.write( "a^2 = 56.25 + 36 - 2(45)*.848<BR>\n" );
document.write( "Do the math, I got:<BR>\n" );
document.write( "a = <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sqrt%2815.92567%29 ALIGN=MIDDLE  ALT=\"sqrt%2815.92567%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "a = 4.0 km  </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );