document.write( "Question 1167615: https://answers.yahoo.com/question/index?qid=20201018140421AAedVNb \n" ); document.write( "
Algebra.Com's Answer #792232 by Theo(13342)\"\" \"About 
You can put this solution on YOUR website!
your problem is shown below:\r
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\n" ); document.write( "let y = f(x).
\n" ); document.write( "the function becomes y = -x^2 + 8x - 7\r
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\n" ); document.write( "\n" ); document.write( "the standard form of a quadratic equation is y = ax^2 + bx + c
\n" ); document.write( "a is the coefficient of the x^2 term.
\n" ); document.write( "b is the coefficient of the x term.
\n" ); document.write( "c is the constant term.\r
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\n" ); document.write( "\n" ); document.write( "the standard form of the equation becomes y = -x^2 + 8x - 7\r
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\n" ); document.write( "\n" ); document.write( "the vertex form of a quadratic equation is y = a(x - h)^2 + k, where (h, k) is the vertex of the parabola.
\n" ); document.write( "a is the coefficient of the x^2 term,
\n" ); document.write( "(h,k) is the coordinates of the vertex.\r
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\n" ); document.write( "\n" ); document.write( "from the standard form of the equation, you would solve for the x-coordinate of the vertex by the following equation:
\n" ); document.write( "x = -b/(2a)
\n" ); document.write( "when b = 8 and a = -1, this becomes x = -8/(-2) = 4.
\n" ); document.write( "the y-coordinate of the vertex is found by replacing x in the standard form of the equation by 4 and solving for y.
\n" ); document.write( "you get y = -4^2 + 8*4 - 7 which becomes y = -16 + 32 - 7.
\n" ); document.write( "solve for y to get y = 9.\r
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\n" ); document.write( "\n" ); document.write( "the vertex from the standard form of the equation is (x,y) = (4,9).
\n" ); document.write( "the vertex from the vertex form of the equation is (h,k) = (4,9).\r
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\n" ); document.write( "\n" ); document.write( "the vertex form of the equation becomes y = -1 * (x-4)^2 + 9.\r
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\n" ); document.write( "\n" ); document.write( "both standard form of the equation and vertex form of the equation can be seen in the following graph.\r
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\n" ); document.write( "\n" ); document.write( "since both equations are equivalent, they both draw the same graph.\r
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\n" ); document.write( "\n" ); document.write( "when you bring the equations down 5 units, you just subtract 5 from the constant term in the standard equation and you drop 5 from the value of k in the vertex form of the equation.\r
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\n" ); document.write( "\n" ); document.write( "you get:\r
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\n" ); document.write( "\n" ); document.write( "y = -x^2 + 8x - 12 in the standard form.
\n" ); document.write( "y = -(x-4)^2 + 4 in the vertex form.\r
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\n" ); document.write( "\n" ); document.write( "both standard form of the equation and vertex form of the equation can be seen in the following graph.\r
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\n" ); document.write( "\n" ); document.write( "you can see from both graphs that the vertex was dropped 5 units from (4,9) to (4,4).\r
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\n" ); document.write( "\n" ); document.write( "here's a reference you might find helpful.\r
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\n" ); document.write( "\n" ); document.write( "https://www.mathwarehouse.com/geometry/parabola/standard-and-vertex-form.php\r
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