document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1108426>Question 1108426</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Write as a trigonometry ratio of A, with the correct sign attached:<BR>\n" );
document.write( "sin(90-A) \r<BR>\n" );
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document.write( "I don't understand why the answer is cos A instead of sin A, could someone please explain?\r<BR>\n" );
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document.write( "Similarly, for:\r<BR>\n" );
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document.write( "sin (90+A)\r<BR>\n" );
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document.write( "I don't understand why the answer is still cos A instead of sin A </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #723454 by </B><A HREF=/tutors/aboutme.mpl?userid=Alan3354><B>Alan3354(69443)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Alan3354><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=Alan3354><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=723454\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Write as a trigonometry ratio of A, with the correct sign attached:<BR>\n" );
document.write( "sin(90-A) \r<BR>\n" );
document.write( "\n" );
document.write( "I don't understand why the answer is cos A instead of sin A, could someone please explain?<BR>\n" );
document.write( "===============<BR>\n" );
document.write( "90-A is the complement of A.<BR>\n" );
document.write( "cosine is the complement of the sine.<BR>\n" );
document.write( "It's a definition.<BR>\n" );
document.write( "You can confirm it using the sum of angles:<BR>\n" );
document.write( "sin(90-A) = sin(90)cos(A) - sin(A)cos(90) = cos(A)<BR>\n" );
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document.write( "Similarly, for:\r<BR>\n" );
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document.write( "sin (90+A)\r<BR>\n" );
document.write( "\n" );
document.write( "I don't understand why the answer is still cos A instead of sin A<BR>\n" );
document.write( "-------<BR>\n" );
document.write( "Plot the terminal point of an angle on the unit circle.<BR>\n" );
document.write( "The sin is y/r = y<BR>\n" );
document.write( "Rotate the point 90 degs CCW, and the y value is now x.<BR>\n" );
document.write( "x/r = cosine<BR>\n" );
document.write( "------<BR>\n" );
document.write( "And, as above:<BR>\n" );
document.write( "sin(90+A) = sin(90)cos(A) + sin(A)cos(90) = cos(A)<BR>\n" );
document.write( "The signs, + or minus, can be different depending on angle A. </SPAN>\n" );
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