document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=526607>Question 526607</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How would you go about solving arccos(sin(6)) where 6 is in radians and you cannot use a calculator? The exact value answer is 5pi/2 - 6. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #348873 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=348873\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> How would you go about solving arccos(sin(6)) where 6 is in radians and you cannot use a calculator? The exact value answer is 5pi/2 - 6.<BR>\n" );
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document.write( "There is an identity: cos(90º-x)=sinx<BR>\n" );
document.write( "In radian form, cos(&#960;/2-x)=sinx<BR>\n" );
document.write( "so, arccos(sin(6)=arccos(cos(&#960;/2-6))<BR>\n" );
document.write( "The inverse of its function is the angle of the function, (&#960;/2-6) radians<BR>\n" );
document.write( "The answer you gave, 5&#960;/2-6 will give you the same value, cos(&#960;/2-6)=-0.279415, cos(5&#960;/2-6)=-0.279415.<BR>\n" );
document.write( "In fact, I found that any odd multiple of &#960;/2, like 3&#960;/2, 7&#960;/2, 9&#960;/2, etc will give the same value of the cos of the angle. So, the answer should be n&#960;/2-6, n=odd integer<BR>\n" );
document.write( "I am not yet smart enough to figure out why this is so.  Maybe your teacher can explain. </SPAN>\n" );
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