document.write( "Question 1065005: If the equation \"sqrt%282%29x%5E2+-+sqrt%283%29x+%2B+k+=+0\" with k a constant has two solutions \"sin%28theta%29\" and \"cos%28theta%29\" (0<=theta<=pi/2),then k = ...\r
\n" ); document.write( "\n" ); document.write( "Hi, I got \"3%2F4sqrt%282%29+%3E+k\". What should I do next? Do I need to pick some lesser number than that?
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Algebra.Com's Answer #680143 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
I agree that \"3%2F4sqrt%282%29+%3E=+k\" is necessary
\n" ); document.write( "to get two real solutions, \"d\" and \"e\" ,
\n" ); document.write( "but we need more than that,
\n" ); document.write( "and trying to use the quadratic formula seems awkward in this case.
\n" ); document.write( "I would say that it is necessary and sufficient
\n" ); document.write( "to have two real solutions, \"d\" and \"e\" ,
\n" ); document.write( "such that \"system%28d%3E=0%2Ce%3E=0%2Cd%5E2%2Be%5E2=1%29\" .
\n" ); document.write( "For any quadratic equation, we know that
\n" ); document.write( "if \"d\" and \"e\" are solutions to \"ax%5E2+%2Bbx+%2B+c+=+0\" ,
\n" ); document.write( "\"system%28de=c%2Fa%2C%22and%22%2Cd%2Be=-b%2Fa%29%29\" .
\n" ); document.write( "In this case,
\n" ); document.write( "if \"d\" and \"e\" are solutions to \"sqrt%282%29x%5E2+-+sqrt%283%29x+%2B+k+=+0\" ,
\n" ); document.write( "\"system%28de=k%2Fsqrt%282%29%2C%22and%22%2Cd%2Be=sqrt%283%29%2Fsqrt%282%29%29\" .
\n" ); document.write( "With \"k%3E=0\" , we would have \"de=k%2Fsqrt%282%29%3E0\" , meaning \"d%3E=0\" and \"e%3E=0\" .
\n" ); document.write( "Let us see if we can find a \"k%3E=0\" out of
\n" ); document.write( "\"system%28d%5E2%2Be%5E2=1%2Cde=k%2Fsqrt%282%29%2Cd%2Be=sqrt%283%29%2Fsqrt%282%29%29\" .
\n" ); document.write( "\"system%28d%5E2%2Be%5E2=1%2Cde=k%2Fsqrt%282%29%2Cd%2Be=sqrt%283%29%2Fsqrt%282%29%29\" --> \"system%28d%5E2%2Be%5E2=1%2C2de=2k%2Fsqrt%282%29%2C%28d%2Be%29%5E2=3%2F2%29\" --> \"system%28d%5E2%2Be%5E2=1%2C2de=2k%2Fsqrt%282%29%2Cd%5E2%2Be%5E2%2B2de=3%2F2%29\" --> \"system%28d%5E2%2Be%5E2=1%2C2de=2k%2Fsqrt%282%29%2C1%2B2k%2Fsqrt%282%29=3%2F2%29\" --> \"system%28d%5E2%2Be%5E2=1%2C2de=2k%2Fsqrt%282%29%2C2k%2Fsqrt%282%29=1%2F2%29\" --> \"system%28d%5E2%2Be%5E2=1%2C2de=2k%2Fsqrt%282%29%2Chighlight%28k=sqrt%282%29%2F4%29%29\"
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\n" ); document.write( "NOTE:
\n" ); document.write( "The solutions to \"sqrt%282%29x%5E2+-+sqrt%283%29x+%2B+k+=+0\" are
\n" ); document.write( "\"x=%28sqrt%283%29+%2B-+1%29%2F%282sqrt%282%29%29\" ,
\n" ); document.write( "which correspond to
\n" ); document.write( "\"system%28theta=pi%2F12%2C%22or%22%2Ctheta=5pi%2F12%29\"
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