document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=632564>Question 632564</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Speed of sound through water caries by temperature<BR>\n" );
document.write( "s=-0.0276t^2 + 9.1558t + 4354.7 (between freezing and boiling)<BR>\n" );
document.write( "s= speed in feet/second, t= temperature Fahrenheit\r<BR>\n" );
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document.write( "I dropped a loud waterproof buzzer in the ocean. My friend who was 4700 feet away heard it 1 second later. What is the temperature of the water? (nearest degree fahrenheit) </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #398367 by </B><A HREF=/tutors/aboutme.mpl?userid=nerdybill><B>nerdybill(7384)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nerdybill><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=nerdybill><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=398367\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Speed of sound through water caries by temperature<BR>\n" );
document.write( "s=-0.0276t^2 + 9.1558t + 4354.7 (between freezing and boiling)<BR>\n" );
document.write( "s= speed in feet/second, t= temperature Fahrenheit<BR>\n" );
document.write( "I dropped a loud waterproof buzzer in the ocean. My friend who was 4700 feet away heard it 1 second later. What is the temperature of the water? (nearest degree fahrenheit)<BR>\n" );
document.write( ".<BR>\n" );
document.write( "Set s to 4700/1 and solve for t:<BR>\n" );
document.write( "4700 = -0.0276t^2 + 9.1558t + 4354.7<BR>\n" );
document.write( "0 = -0.0276t^2 + 9.1558t - 345.3<BR>\n" );
document.write( "Using the \"quadratic equation\" we get:<BR>\n" );
document.write( "x = {43.4, 288.3}<BR>\n" );
document.write( "Throw out the 288 because it is outside the boiling point leaving:<BR>\n" );
document.write( "x = 43 degrees<BR>\n" );
document.write( ".<BR>\n" );
document.write( "Details of quadratic formula:<BR>\n" );
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document.write( " <TR><TD  ALIGN=MIDDLE>Solved by <A  rel=nofollow HREF=http://wiki.algebra.com/index.php/Tutoring_-_pluggable_solvers>pluggable</A> solver: <A  rel=nofollow HREF=quadratic.solver>SOLVE quadratic equation with variable</A></TD></TR>\n" );
document.write( "<TR><TD  ALIGN=LEFT>Quadratic equation <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ax%5E2%2Bbx%2Bc=0 ALIGN=MIDDLE  ALT=\"ax%5E2%2Bbx%2Bc=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > (in our case <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-0.0276x%5E2%2B9.1558x%2B-345.3+=+0 ALIGN=MIDDLE  ALT=\"-0.0276x%5E2%2B9.1558x%2B-345.3+=+0\"   DISABLED_style= \"max-width:90%; height:auto;\" >) has the following solutons:<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca ALIGN=MIDDLE  ALT=\"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  <BR>\n" );
document.write( "  For these solutions to exist, the <U>discriminant</U> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac ALIGN=MIDDLE  ALT=\"b%5E2-4ac\"   DISABLED_style= \"max-width:90%; height:auto;\" > should not be a negative number.<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  First, we need to compute the discriminant <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac ALIGN=MIDDLE  ALT=\"b%5E2-4ac\"   DISABLED_style= \"max-width:90%; height:auto;\" >: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b%5E2-4ac=%289.1558%29%5E2-4%2A-0.0276%2A-345.3=45.70755364 ALIGN=MIDDLE  ALT=\"b%5E2-4ac=%289.1558%29%5E2-4%2A-0.0276%2A-345.3=45.70755364\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "  <BR>\n" );
document.write( "  Discriminant d=45.70755364 is greater than zero. That means that there are two solutions: <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+x%5B12%5D+=+%28-9.1558%2B-sqrt%28+45.70755364+%29%29%2F2%5Ca ALIGN=MIDDLE  ALT=\"+x%5B12%5D+=+%28-9.1558%2B-sqrt%28+45.70755364+%29%29%2F2%5Ca\"   DISABLED_style= \"max-width:90%; height:auto;\" >.<BR>\n" );
document.write( "  <BR>\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5B1%5D+=+%28-%289.1558%29%2Bsqrt%28+45.70755364+%29%29%2F2%5C-0.0276+=+43.3888373932807 ALIGN=MIDDLE  ALT=\"x%5B1%5D+=+%28-%289.1558%29%2Bsqrt%28+45.70755364+%29%29%2F2%5C-0.0276+=+43.3888373932807\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x%5B2%5D+=+%28-%289.1558%29-sqrt%28+45.70755364+%29%29%2F2%5C-0.0276+=+288.34304666469 ALIGN=MIDDLE  ALT=\"x%5B2%5D+=+%28-%289.1558%29-sqrt%28+45.70755364+%29%29%2F2%5C-0.0276+=+288.34304666469\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "    <BR>\n" );
document.write( "    Quadratic expression <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-0.0276x%5E2%2B9.1558x%2B-345.3 ALIGN=MIDDLE  ALT=\"-0.0276x%5E2%2B9.1558x%2B-345.3\"   DISABLED_style= \"max-width:90%; height:auto;\" > can be factored:<BR>\n" );
document.write( "  <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=-0.0276x%5E2%2B9.1558x%2B-345.3+=+-0.0276%28x-43.3888373932807%29%2A%28x-288.34304666469%29 ALIGN=MIDDLE  ALT=\"-0.0276x%5E2%2B9.1558x%2B-345.3+=+-0.0276%28x-43.3888373932807%29%2A%28x-288.34304666469%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "  Again, the answer is: 43.3888373932807, 288.34304666469.\n" );
document.write( "Here's your graph:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-0.0276%2Ax%5E2%2B9.1558%2Ax%2B-345.3+%29 ALIGN=MIDDLE  ALT=\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+-0.0276%2Ax%5E2%2B9.1558%2Ax%2B-345.3+%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ></TD></TR>\n" );
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document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );