document.write( "Question 1198721: Given cos theta = -1/5 and tan theta < 0, find cot theta and sin theta. \n" ); document.write( "
Algebra.Com's Answer #832551 by MathLover1(20850)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "Given: \r
\n" ); document.write( "\n" ); document.write( " \"cos%28+theta%29+=+-1%2F5\" and \"tan+%28theta%29+%3C+0\"\r
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\n" ); document.write( "\n" ); document.write( "find:\r
\n" ); document.write( "\n" ); document.write( " \"cot+%28theta%29\" and \"sin+%28theta%29\"\r
\n" ); document.write( "\n" ); document.write( "Start with the identity:\r
\n" ); document.write( "\n" ); document.write( " \"cos%5E2%28+theta%29+=1-sin%5E2%28theta%29\"\r
\n" ); document.write( "\n" ); document.write( "Substitute \"cos%28+theta%29+=+-1%2F5\"\r
\n" ); document.write( "\n" ); document.write( "\"-1%2F5=1-sin%5E2%28theta%29\"\r
\n" ); document.write( "\n" ); document.write( "\"sin%5E2%28theta%29=1-1%2F5\"\r
\n" ); document.write( "\n" ); document.write( "\"sin%5E2%28theta%29=4%2F5\"\r
\n" ); document.write( "\n" ); document.write( "\"sin%28theta%29\"\"sqrt%284%2F5%29\"\r
\n" ); document.write( "\n" ); document.write( "\"sin%28theta%29\"\"%282sqrt%285%29%29%2F5\"\r
\n" ); document.write( "\n" ); document.write( " \"tan+%28theta%29+%3C+0\"=>\"sin%28theta%29=-%282sqrt%285%29%29%2F5\"\r
\n" ); document.write( "\n" ); document.write( "then\r
\n" ); document.write( "\n" ); document.write( "\"cos%5E2%28+theta%29+=1-%28-%282sqrt%285%29%29%2F5%29%5E2\"
\n" ); document.write( "\"cos%5E2%28+theta%29+=1%2F5\"
\n" ); document.write( "\"cos%28+theta%29\"\"sqrt%281%2F5%29\"
\n" ); document.write( "\"cos%28+theta%29+\"=±sqrt(5)/5}}}\r
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\n" ); document.write( "\n" ); document.write( "\"cot+%28theta%29=cos%28theta%29%2Fsin%28theta%29\"...........since \"tan+%28theta%29%3C0+\" and \"sin%28theta%29=-%282sqrt%285%29%29%2F5\", use positive solution for cos\r
\n" ); document.write( "\n" ); document.write( "\"cos%28+theta%29+=sqrt%285%29%2F5\"\r
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\n" ); document.write( "\n" ); document.write( "so,\r
\n" ); document.write( "\n" ); document.write( "\"cot+%28theta%29=%28sqrt%285%29%2F5%29%2F%28-%282sqrt%285%29%29%2F5%29\"\r
\n" ); document.write( "\n" ); document.write( "\"cot+%28theta%29=-1%2F2\"\r
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