document.write( "Question 1207455: ABC is a triangle with ∠CAB=15
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\n" ); document.write( " . If M is the midpoint of AB, Sin then ∠ACM= ? \n" ); document.write( "

Algebra.Com's Answer #845439 by Edwin McCravy(20055) $\"\"$ $\"About$

You can put this solution on YOUR website!
I just ignored \"Sin\".
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document.write( "This problem would be much easier if you could use decimals, but \r\n" );
document.write( "decimals are approximate. The answer could only be approximate if we \r\n" );
document.write( "use decimals, so we must use exact values.  Maybe some other tutor can \r\n" );
document.write( "come up with a shorter solution, but this was the very long solution I \r\n" );
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document.write( "We want to find angle θ \r\n" );
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document.write( "Without loss of generality we can let AM = MB = 1 unit.\r\n" );
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document.write( "We are going to need expressions for both sine and cosine of 15^o.\r\n" );
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document.write( "Angle ACB = 180^o-15^o-30^o = 135^o.\r\n" );
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document.write( "By the law of sines on triangle ABC.\r\n" );
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document.write( "By the law of cosines on triangle ACM\r\n" );
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document.write( "Now let's see if we can rewrite that so it doesn't have a \r\n" );
document.write( "square root under a square root.  We'll see if we can write\r\n" );
document.write( "it as the difference of 2 square roots:\r\n" );
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document.write( "=>\r\n" );
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document.write( " =>  => \r\n" );
document.write( "CM can't be negative, so \r\n" );
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document.write( "Use the law of sines on triangle ACM:\r\n" );
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document.write( "Edwin

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