document.write( "Question 825876: For what values of k does 2x^2 - 5x - k = 0 have no real roots?
\n" ); document.write( "Can you please help me out? Thanks so much in advance:)
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Algebra.Com's Answer #497661 by josmiceli(19441)\"\" \"About 
You can put this solution on YOUR website!
\"+2x%5E2+-+5x+-+k+=+0+\"
\n" ); document.write( "Use the quadratic formula
\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+\"
\n" ); document.write( "\"+a+=+2+\"
\n" ); document.write( "\"+b+=+-5+\"
\n" ); document.write( "\"+c+=+-k+\"
\n" ); document.write( "the roots are imaginary when \"+b%5E2+-+4%2Aa%2Ac+\"
\n" ); document.write( "is negative. Since \"+b%5E2+\" is always positive.
\n" ); document.write( "\"+4%2Aa%2Ac+%3E+b%5E2+\"
\n" ); document.write( "\"+4%2A2%2A%28-k%29+%3E+%28-5%29%5E2+\"
\n" ); document.write( "\"+-8%2Ak+%3E+25+\"
\n" ); document.write( "\"+k+%3C+-25%2F8+\" answer
\n" ); document.write( "( note that I had to reverse the inequality sign
\n" ); document.write( "when I divided by a negative number )
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\n" ); document.write( "Suppose \"+k+=+-25%2F8+\"
\n" ); document.write( " \"+b%5E2+-+4%2Aa%2Ac+=+%28-5%29%5E2+-+4%2A2%2A%28-k%29+\"
\n" ); document.write( " \"+b%5E2+-+4%2Aa%2Ac+=+25+-+4%2A2%2A%28-%28-25%2F8%29%29+\"
\n" ); document.write( " \"+b%5E2+-+4%2Aa%2Ac+=+25+-+25+\"
\n" ); document.write( "\"+b%5E2+-+4%2Aa%2Ac+=+0+\"
\n" ); document.write( "That means there is 1 real root
\n" ); document.write( "---------------------------
\n" ); document.write( "Suppose \"+k+=+-26%2F8+\" or
\n" ); document.write( "\"+k+=+-13%2F4+\"
\n" ); document.write( "\"+b%5E2+-+4%2Aa%2Ac+=+%28-5%29%5E2+-+4%2A2%2A%28-k%29+\"
\n" ); document.write( "\"+b%5E2+-+4%2Aa%2Ac+=+25+-+4%2A2%2A%28-%28-13%2F4%29%29+\"
\n" ); document.write( "\"+b%5E2+-+4%2Aa%2Ac+=+25+-+26+\"
\n" ); document.write( "\"+b%5E2+-+4%2Aa%2Ac+=+-1+\"
\n" ); document.write( "That means there are 2 imaginary roots\r
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