document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1205097>Question 1205097</A>: <I><SPAN STYLE=\"word-break: break-all;\"> So I tried calculating the Cotangent of <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=pi+%2F+2 ALIGN=MIDDLE  ALT=\"pi+%2F+2\"   DISABLED_style= \"max-width:90%; height:auto;\" > (90 degrees). The answer is 0, but my scientific calculator (Casio Fx300ES Plus) didn't say that. \r<BR>\n" );
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document.write( "I inputted: <BR>\n" );
document.write( " ‍‍   ‍‍ ‍<IMG STYLE=\"max-width:80%;\" src=\"https://i.ibb.co/kqgDT0M/Code-Cogs-Eqn.gif\" width=\"60px\">\r<BR>\n" );
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document.write( "But I got a Math ERROR. The answer is 0, not undefined? Why's that? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #841726 by </B><A HREF=/tutors/aboutme.mpl?userid=MathLover1><B>MathLover1(20850)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=MathLover1><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=MathLover1><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=841726\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cot%28pi%2F2%29=1%2Ftan%28pi%2F2%29 ALIGN=MIDDLE  ALT=\"cot%28pi%2F2%29=1%2Ftan%28pi%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=tan%28pi%2F2%29=infinity ALIGN=MIDDLE  ALT=\"tan%28pi%2F2%29=infinity\"   DISABLED_style= \"max-width:90%; height:auto;\" >, you have <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cot%28pi%2F2%29=1%2Finfinity ALIGN=MIDDLE  ALT=\"cot%28pi%2F2%29=1%2Finfinity\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "so you need to use identity <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=tan%28pi%2F2%29=sin%28pi%2F2%29%2Fcos%28pi%2F2%29 ALIGN=MIDDLE  ALT=\"tan%28pi%2F2%29=sin%28pi%2F2%29%2Fcos%28pi%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >, then you have\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cot%28pi%2F2%29=1%2F%28sin%28pi%2F2%29%2Fcos%28pi%2F2%29%29 ALIGN=MIDDLE  ALT=\"cot%28pi%2F2%29=1%2F%28sin%28pi%2F2%29%2Fcos%28pi%2F2%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cot%28+pi%2F2%29=cos%28pi%2F2%29%2Fsin%28pi%2F2%29 ALIGN=MIDDLE  ALT=\"cot%28+pi%2F2%29=cos%28pi%2F2%29%2Fsin%28pi%2F2%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >.....since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cos%28pi%2F2%29=0 ALIGN=MIDDLE  ALT=\"cos%28pi%2F2%29=0\"   DISABLED_style= \"max-width:90%; height:auto;\" > and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sin%28pi%2F2%29=1 ALIGN=MIDDLE  ALT=\"sin%28pi%2F2%29=1\"   DISABLED_style= \"max-width:90%; height:auto;\" >, you have\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cot%28+pi%2F2%29=0%2F1 ALIGN=MIDDLE  ALT=\"cot%28+pi%2F2%29=0%2F1\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=cot%28+pi%2F2%29=0 ALIGN=MIDDLE  ALT=\"cot%28+pi%2F2%29=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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