document.write( "Question 1024230: how do you write y=(x-4)(x+2) in standard form?
\n" ); document.write( "with the standard form of the equation use the quadratic formula to identify the x-value of the vertex. use the quadratic formula with the vertex -b/2a then substitute the x-value of the vertex into the original equation to find the y-value of the vertex then write the coordinates of the vertex. what are the 3 points to graph an parabola? PLEASE HELP \n" ); document.write( "

Algebra.Com's Answer #639702 by robertb(5830) $\"\"$ $\"About$

You can put this solution on YOUR website!
You don't even have to use formulas to find the vertex of the parabola if you know the roots.\r
\n" ); document.write( "\n" ); document.write( "y = (x-4)(x+2) ==> the roots of the equation are 4 and -2. The x-coordinate of the vertex should be the average of the two roots, namely $\"%284%2B%28-2%29%29%2F2+=+1\"$ . To find the y-coordinate of the vertex plug it into the original equation:
\n" ); document.write( "y = (1-4)(1+2) = -3*3 = -9.
\n" ); document.write( "==> (h,k) = (1,-9)\r
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\n" ); document.write( "\n" ); document.write( "==> $\"y+=+x%5E2+-+2x+-+8\"$ , the standard form of the equation \n" ); document.write( "

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