document.write( "Question 1000272: Plz help me to explain the range of this equation...{x^2-2x-3=0} \n" ); document.write( "
Algebra.Com's Answer #617808 by MathLover1(20849)\"\" \"About 
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\n" ); document.write( "\n" ); document.write( "As with any function, the domain of a quadratic function f(x) is the set of x-values for which the function is defined, and the range is the set of all the output values (values of f).\r
\n" ); document.write( "\n" ); document.write( "Quadratic functions generally have the whole real line as their domain:
\n" ); document.write( "any \"x\" is a legitimate input.
\n" ); document.write( "The range is \"restricted\" to those points greater than or equal to the \"y-coordinate\" of the \"vertex\" (or less than or equal to, depending on whether the parabola opens \"up\" or \"down\"). \r
\n" ); document.write( "\n" ); document.write( "you are given \"x%5E2-2x-3=0\" ...since coefficient \"a=1\" which is positive number, your parabola opens \"up\"\r
\n" ); document.write( "\n" ); document.write( "The equation for a parabola can also be written in \"vertex form\":\r
\n" ); document.write( "\n" ); document.write( "\"y+=+a%28x+-+h%29%5E2+%2B+k\"
\n" ); document.write( "\"y=x%5E2-2x-3\"\r
\n" ); document.write( "\n" ); document.write( "\"y=%28x%5E2-2x%2Bb%5E2%29-b%5E2-3\"\r
\n" ); document.write( "\n" ); document.write( "\"y=%28x%5E2-2x%2B1%5E2%29-1%5E2-3\"
\n" ); document.write( "\"y=%28x-1%29%5E2-1-3\"
\n" ); document.write( "\"y=%28x-1%29%5E2-4\"\r
\n" ); document.write( "\n" ); document.write( "=>\"h=1\" and \"k=-4\"
\n" ); document.write( "the \"vertex\" of your parabola is at (\"1\",\"-4\")\r
\n" ); document.write( "\n" ); document.write( "so, the range will be all values of \"y\" from \"-4\" to \"infinity\"\r
\n" ); document.write( "\n" ); document.write( "or { \"y\" element of \"R\": \"y%3E=-4\" }\r
\n" ); document.write( "\n" ); document.write( "in interval notation:\r
\n" ); document.write( "\n" ); document.write( "[\"-4\",\"infinity\")\r
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\n" ); document.write( "\n" ); document.write( " \"+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+%28x-1%29%5E2-4%29+\"\r
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