document.write( "Question 302828: 3cos^2 2x - 2sin^2 2x = 2 - 4sin2x\r
\n" ); document.write( "\n" ); document.write( "find all the angles between 0degrees to 180degrees inclusive which satisfy equation\r
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\n" ); document.write( "\n" ); document.write( "--x-x-x-x-x-x-x-x-x--\r
\n" ); document.write( "\n" ); document.write( "express 1/ (x-3)(2x +1) as partial fractions\r
\n" ); document.write( "\n" ); document.write( "hence evaluate (cant really draw it out but.... evaluate definite integral 7 on top, 4 below. 1/(x-3)(2x +1)
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Algebra.Com's Answer #217102 by Fombitz(32388)\"\" \"About 
You can put this solution on YOUR website!
Let \"S=sin%282x%29\" and \"C=cos%282x%29\" to reduce the clutter,
\n" ); document.write( "\"3C%5E2-2S%5E2+=+2+-+4S\"
\n" ); document.write( "\"3C%5E2-2S%5E2%2B4S-2+=0\"
\n" ); document.write( "Remember that
\n" ); document.write( "\"C%5E2%2BS%5E2=1\"
\n" ); document.write( "\"C%5E2=1-S%5E2\"
\n" ); document.write( "\"3C%5E2=3-3S%5E2\"
\n" ); document.write( "Substitute,
\n" ); document.write( "\"%283-3S%5E2%29-2S%5E2%2B4S-2=0\"
\n" ); document.write( "\"-5S%5E2%2B4S%2B1=0\"
\n" ); document.write( "\"5S%5E2-4S-1=0\"
\n" ); document.write( "You can factor,
\n" ); document.write( "\"%285S%2B1%29%28S-1%29=0\"
\n" ); document.write( "Two solutions:
\n" ); document.write( "\"5S%2B1=0\"
\n" ); document.write( "\"S=-1%2F5\"
\n" ); document.write( "\"sin%282x%29=-1%2F5\"
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\n" ); document.write( "\"S-1=0\"
\n" ); document.write( "\"S=1\"
\n" ); document.write( "\"sin%282x%29=1\"
\n" ); document.write( "I leave those to you to complete.
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\n" ); document.write( "Partial fractions.
\n" ); document.write( " \"1%2F+%28%28x-3%29%282x+%2B1%29%29+=A%2F%28x-3%29%2BB%2F%282x%2B1%29\"
\n" ); document.write( "Multiply by \"%28x-3%29%282x%2B1%29\"
\n" ); document.write( "\"1=A%282x%2B1%29%2BB%28x-3%29\"
\n" ); document.write( "\"%282Ax%2BBx%29%2B%28A-3B%29=1\"
\n" ); document.write( "Leads to two equations,
\n" ); document.write( "1.\"2A%2BB=0\"
\n" ); document.write( "2.\"A-3B=1\"
\n" ); document.write( "Multiply eq.1 by 3 and add the two together to solve for A.
\n" ); document.write( "\"6A%2B3B%2BA-3B=1\"
\n" ); document.write( "\"7A=1\"
\n" ); document.write( "\"A=1%2F7\"
\n" ); document.write( "Then use either equation to solve for B.
\n" ); document.write( "\"2A%2BB=0\"
\n" ); document.write( "\"B=-2A=-2%2F7\"\r
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\n" ); document.write( "If you integrate you'll get
\n" ); document.write( "INT=\"%281%2F7%29ln%28x-3%29-%282%2F7%29ln%282x%2B1%29\" evaluated between \"x=4\" and \"x=7\".
\n" ); document.write( "I leave those to you to complete.
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