document.write( "Question 139966: A parabola passes through (-2,0),(4,0) and (5,14).
\n" ); document.write( "Find the equation of the axis of symmetry.
\n" ); document.write( "Find the equation of the line perpendicular to the Y-axis that passes through exactly one point of the parabola.
\n" ); document.write( "find the equation of the parabola.\r
\n" ); document.write( "\n" ); document.write( "I just do not know where to start, what to look for first. Please help. Thankyou. \n" ); document.write( "
Algebra.Com's Answer #102014 by scott8148(6628)\"\" \"About 
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the first two points have the same y-coordinate, so the axis of symmetry is a vertical line (x=?) midway between them
\n" ); document.write( "__ x=(-2+4)/2 __ x=1\r
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\n" ); document.write( "\n" ); document.write( "the y value of the first two points is zero, so these are the roots of the quadratic equation
\n" ); document.write( "__ if -2 and 4 are roots, then x+2 and x-4 are factors
\n" ); document.write( "__ there may also be a constant factor that is related to the shape of the graph\r
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\n" ); document.write( "\n" ); document.write( "y=k(x+2)(x-4) __ using the 3rd point __ 14=k(5+2)(5-4) __ 2=k
\n" ); document.write( "__ so y=2(x+2)(x-4)\r
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\n" ); document.write( "\n" ); document.write( "the line through one point passes through the vertex, which lies on the axis of symmetry
\n" ); document.write( "__ substituting __ y=2(1+2)(1-4) __ y=-18 \n" ); document.write( "
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