the equation of the parabola is 2x^2-4x+5.
1)If the parabola is shifted horizontally so that the y-axis becomes its line of symmetry, what will be the new equation of the parabola?
更新1:
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A.MATHS urgent~
2008-09-26 12:34 am
a parabola has the vertex at V (1,3) and it cuts the y-axis at A (0,5).
the equation of the parabola is 2x^2-4x+5.
1)If the parabola is shifted horizontally so that the y-axis becomes its line of symmetry, what will be the new equation of the parabola?
the equation of the parabola is 2x^2-4x+5.
1)If the parabola is shifted horizontally so that the y-axis becomes its line of symmetry, what will be the new equation of the parabola?
回答 (2)
2008-09-26 2:07 am
✔ 最佳答案
y = 2x^2 - 4x + 5= 2(x^2 -2x) + 5
= 2[(x - 1)^2 - 1] + 5
= 2(x - 1)^2 - 2 + 5
= 2( x - 1)^2 + 3.
Now the axis of symmetry is x = 1. If you want the axis of symmetry to be the y -axis, that is x = 0, so you shift it to the left by 1 unit, that is from (x - 1) to
[(x + 1) - 1] = x.
So the new equation is
y = 2x^2 + 3.
2008-09-26 12:42 am
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