You can put this solution on YOUR website! Please help to complete the square and graph :
y = x^2 + 2x - 1
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Put it in the "complete the square" arrangement
x^2 + 2x + ___ = +1
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The 3rd term is equal to the coefficient of x divide by 2 and then squared:
2/2 = 1, 1^2 = 1
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x^2 + 2x + 1 = 1 + 1; added 1 to both sides, to maintain equality
x^2 + 2x + 1 = 2
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(x + 1)^2 = 2: factored the perfect square
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x + 1 = +-; the square root of both sides
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x = -1 +-; subtracted 1 from both sides
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x = -1 + ; approx +.414
and
x = -1 - ; approx -2.414
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The graph:
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Plot the the graph, solving for y using the equation; x^2 + 2x -1
the table should look like this
x | y
-------
-4 |+7
-3 |+2
-2 |-1
-1 |-2
0 |-1
+1 |+2
+2 |+7
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Note the value of the x intercepts
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Did you follow this? Any questions?
