document.write( "Question 1203962: If $\"+cos%28beta%29+=+-3+%2F+5+\"$ then, without a calculator, find $\"cos%28pi+%2F+2+-+beta%29+\"$ . Write your answer as a fraction. \n" ); document.write( "

Algebra.Com's Answer #839908 by mananth(16946) $\"\"$ $\"About$

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$\"cos%28pi%2F2-beta%29+=+sin%28beta%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"cos%5E2%28beta%29%2Bsin%5E2%28beta%29=+1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"%28-3%2F5%29%5E2%2B+sin%5E2%28beta%29+=1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"9%2F25+%2B+sin%5E2%28beta%29+=+1\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"sin%5E2%28beta%29=+1-+9%2F25\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"sin%5E2%28beta%29+=+16%2F25\"$ \r
\n" ); document.write( "\n" ); document.write( "sin(beta) = (+/-)(4/5)\r
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