document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=329512>Question 329512</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I'm kinda stuck on these three identity Questions: Could you explain how to solve these to me. Please and Thankyou.<BR>\n" );
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document.write( "6. Find the exact value of sin 2 &#952; given that cos &#952; = 12/13 and &#952; is in Quadrant I.<BR>\n" );
document.write( "a. -120/169 <BR>\n" );
document.write( "b. 120/169 <BR>\n" );
document.write( "c. 60/169 <BR>\n" );
document.write( "d. -60/169 <BR>\n" );
document.write( "*sin(2&#952;)=2sin(&#952;)cos(&#952;)<BR>\n" );
document.write( "sin(2&#952;)=2sin(&#952;)cos(12/13)<BR>\n" );
document.write( "sin(2&#952;)=?\r<BR>\n" );
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document.write( "8. Find the value of the tan of a/2 given that cos a = -4/5 and a is in Quadrant II. <BR>\n" );
document.write( "a. 3<BR>\n" );
document.write( "b. 1/2 <BR>\n" );
document.write( "c. -2 <BR>\n" );
document.write( "d. -1/2 <BR>\n" );
document.write( "*tan(a/2)=1-cos(a)/sin(a)<BR>\n" );
document.write( "tan(a/2)=1-cos(-4/5)/sin(1/5)<BR>\n" );
document.write( "tan(a/2)=?\r<BR>\n" );
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document.write( "14. Evaluate sin 165 ° + sin 105 ° . <BR>\n" );
document.write( "*My answer was -&#8730;(2)/2. Am I correct?<BR>\n" );
document.write( "15. Evaluate sin(&#960;/12)-sin((5&#960;)/12).<BR>\n" );
document.write( "*My answer was 1. Am I correct? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #236194 by </B><A HREF=/tutors/aboutme.mpl?userid=nyc_function><B>nyc_function(2741)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=nyc_function><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=nyc_function><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=236194\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> BIG TIP:  Post one question at a time or else no one will reply.\r<BR>\n" );
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document.write( "I will do question 6 only.\r<BR>\n" );
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document.write( "6. Find the exact value of sin 2 &#952; given that cos &#952; = 12/13 and &#952; is in Quadrant I.\r<BR>\n" );
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document.write( "We are in quadrant 1 which means all trig functions are positive.  So, there's no need to worry about signs in this case.\r<BR>\n" );
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document.write( "Using a right triangle in the first quadrant, we know that cos(theta) = adj/hyp.<BR>\n" );
document.write( "Using the Pythagorean Theorem, we also learn that the missing side is 5. \r<BR>\n" );
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document.write( "sin(theta) = opp/hyp\r<BR>\n" );
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document.write( "sin(theta) = 5/13\r<BR>\n" );
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document.write( "cos(theta) = adj/hyp\r<BR>\n" );
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document.write( "cos(theta) = 12/13\r<BR>\n" );
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document.write( "We now plug it into the formula sin(2&#952;) = 2sin(&#952;)cos(&#952;) and simplify.\r<BR>\n" );
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document.write( "sin(2&#952;) = 2(5/13)(12/13)\r<BR>\n" );
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document.write( "sin(2&#952;) = 2(5/13)(12/13)\r<BR>\n" );
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document.write( "sin(2&#952;) = 120/169\r<BR>\n" );
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document.write( "CHOICE B\r<BR>\n" );
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document.write( " </SPAN>\n" );
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