document.write( "Question 948573: Please help me answer this: For what values of k will the equation 3x^2=k-2x have real roots? \n" ); document.write( "
Algebra.Com's Answer #579007 by MathLover1(20849)\"\" \"About 
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\"3x%5E2=k-2x\"
\n" ); document.write( "\"3x%5E2%2B2x-k=0\"=> \"a=3\", \"b=2\", and \"c=-k\"\r
\n" ); document.write( "\n" ); document.write( "The argument of the square root, the expression \"b%5E2+%96+4ac\", is called the \"discriminant\" because, by using its value, you can discriminate between (tell the differences between) the various solution types.\r
\n" ); document.write( "\n" ); document.write( "if \"b%5E2+%96+4ac%3C0\" there is no real roots
\n" ); document.write( "if \"b%5E2+%96+4ac=0\" there is one real roots
\n" ); document.write( "if \"b%5E2+%96+4ac%3E0\" there are two real roots\r
\n" ); document.write( "\n" ); document.write( "so, we need
\n" ); document.write( "if \"b%5E2+%96+4ac=0\" there is one real roots
\n" ); document.write( "if \"b%5E2+%96+4ac%3E0\" there are two real roots\r
\n" ); document.write( "\n" ); document.write( "and I will write both in one as \"b%5E2+%96+4ac%3E=0\"\r
\n" ); document.write( "\n" ); document.write( "now just plug in \"a=3\", \"b=2\", and \"c=-k\"\r
\n" ); document.write( "\n" ); document.write( "\"2%5E2+%96+4%2A3%2A%28-k%29%3E=0\"\r
\n" ); document.write( "\n" ); document.write( "\"4+%96+12%28-k%29%3E=0\"\r
\n" ); document.write( "\n" ); document.write( "\"4+%2B12k%3E=0\"\r
\n" ); document.write( "\n" ); document.write( "\"12k%3E=-4\"\r
\n" ); document.write( "\n" ); document.write( "\"k%3E=-4%2F12\"\r
\n" ); document.write( "\n" ); document.write( "\"k%3E=-1%2F3\"\r
\n" ); document.write( "\n" ); document.write( "so, if \"k=-1%2F3\" we will have one real root which is \"x=-1%2F3\" (you can check it)
\n" ); document.write( "if \"k%3E=-1%2F3\", using for example \"k=0\" we will have two real roots which are \"x+=+0\" and \"x=-2%2F3\"\r
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\n" ); document.write( "\n" ); document.write( "so, to get real root/roots, you can use any value for \"k\" from [\"-1%2F3\",\"infinity\")\r
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