document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1000137>Question 1000137</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me with the problem below:\r<BR>\n" );
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document.write( "The distance y inches between a yo-yo and Susan's had at time t seconds is given by the equation y=-15cos(2(3.14)t/2.8)+15. Steven needs to take a picture when the yo-yo is 7 inches from the hand and moving away from the hand. At what times can he take the picture? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #617664 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=617664\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is telling you that <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+y+=+7+ ALIGN=MIDDLE  ALT=\"+y+=+7+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+=+15%2A%28+-cos%28+6.28t%2F2.8+%29+%2B+1+%29+ ALIGN=MIDDLE  ALT=\"+7+=+15%2A%28+-cos%28+6.28t%2F2.8+%29+%2B+1+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7%2F15+=++-cos%28+6.28t%2F2.8+%29+%2B+1+ ALIGN=MIDDLE  ALT=\"+7%2F15+=++-cos%28+6.28t%2F2.8+%29+%2B+1+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7%2F15+-+15%2F15+=+-cos%28+6.28t%2F2.8+%29+ ALIGN=MIDDLE  ALT=\"+7%2F15+-+15%2F15+=+-cos%28+6.28t%2F2.8+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+8%2F15+=+cos%28+6.28t%2F2.8+%29+ ALIGN=MIDDLE  ALT=\"+8%2F15+=+cos%28+6.28t%2F2.8+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+8%2F15+=+.5333+ ALIGN=MIDDLE  ALT=\"+8%2F15+=+.5333+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+6.28t%2F2.8+=+theta+ ALIGN=MIDDLE  ALT=\"+6.28t%2F2.8+=+theta+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+.5333+=+cos%28+theta+%29+ ALIGN=MIDDLE  ALT=\"+.5333+=+cos%28+theta+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Using the inverse cos function<BR>\n" );
document.write( "and setting for radians <BR>\n" );
document.write( "on my calculator:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+theta+=+1.00826+ ALIGN=MIDDLE  ALT=\"+theta+=+1.00826+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+6.28t%2F2.8+=+1.00826+ ALIGN=MIDDLE  ALT=\"+6.28t%2F2.8+=+1.00826+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+6.28t+=+2.8231+ ALIGN=MIDDLE  ALT=\"+6.28t+=+2.8231+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+=+.4495+ ALIGN=MIDDLE  ALT=\"+t+=+.4495+\"   DISABLED_style= \"max-width:90%; height:auto;\" > sec<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "The cos function ( all cos functions ) begins at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1+ ALIGN=MIDDLE  ALT=\"+1+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, then <BR>\n" );
document.write( "goes to <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+0+ ALIGN=MIDDLE  ALT=\"+0+\"   DISABLED_style= \"max-width:90%; height:auto;\" > at <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+theta+=+pi%2F2+ ALIGN=MIDDLE  ALT=\"+theta+=+pi%2F2+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-----------------<BR>\n" );
document.write( "My value, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+theta+=+1.00826+ ALIGN=MIDDLE  ALT=\"+theta+=+1.00826+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, is less than <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+pi%2F2+ ALIGN=MIDDLE  ALT=\"+pi%2F2+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, so<BR>\n" );
document.write( "it is on the way down from zero inches from hand to<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+15+ ALIGN=MIDDLE  ALT=\"+15+\"   DISABLED_style= \"max-width:90%; height:auto;\" > inches from hand when cos function is zero.  <BR>\n" );
document.write( "When the cos is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+-1+ ALIGN=MIDDLE  ALT=\"+-1+\"   DISABLED_style= \"max-width:90%; height:auto;\" >,<BR>\n" );
document.write( "yo-yo is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+30+ ALIGN=MIDDLE  ALT=\"+30+\"   DISABLED_style= \"max-width:90%; height:auto;\" > inches from hand.<BR>\n" );
document.write( "-------------------------------<BR>\n" );
document.write( "To figure out all the times that yo-yo is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+ ALIGN=MIDDLE  ALT=\"+7+\"   DISABLED_style= \"max-width:90%; height:auto;\" > in from hand<BR>\n" );
document.write( "and on the way down, you must add <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%2Api+ ALIGN=MIDDLE  ALT=\"+2%2Api+\"   DISABLED_style= \"max-width:90%; height:auto;\" > like this:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+=+15%2A%28+-cos%28+6.28t%2F2.8+%2B+2%2Api+%29+%2B+1+%29+ ALIGN=MIDDLE  ALT=\"+7+=+15%2A%28+-cos%28+6.28t%2F2.8+%2B+2%2Api+%29+%2B+1+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Then you must find <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t+ ALIGN=MIDDLE  ALT=\"+t+\"   DISABLED_style= \"max-width:90%; height:auto;\" > for <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+2%2Api+ ALIGN=MIDDLE  ALT=\"+2%2Api+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+4%2Api+ ALIGN=MIDDLE  ALT=\"+4%2Api+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+6%2Api+ ALIGN=MIDDLE  ALT=\"+6%2Api+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, etc.<BR>\n" );
document.write( "You will be on the way down each of those times and<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+7+ ALIGN=MIDDLE  ALT=\"+7+\"   DISABLED_style= \"max-width:90%; height:auto;\" > in from hand<BR>\n" );
document.write( "--------------------<BR>\n" );
document.write( "Hope this helps </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );