siuming asked in 科學及數學數學 · 1 decade ago

我想問點求一條二次方程既頂點?

例如點求x^2-4x-5=0既頂點?

請詳細一d...謝謝

Update:

如果依條二次方程同一條直線有兩個交點(5,6),(-1,-6),咁點求個頂點同兩個交點內既範圍?

1 Answer

Rating
  • Athrun
    Lv 6
    1 decade ago
    Favorite Answer

    By using completing squares:

    It should be function or we cannot draw it.

    y=x^2-4x-5

    y=x^2-4x+4-9

    y=(x-2)^2-9

    formula: y=a(x-h)^2-k

    vertex(h,k)

    So, the vertex is the minimum point (2,-9)

    You have two functions, you cannot have vertex.

    範圍: You should be taught in A.Maths in F5 by using integration

    2007-08-28 14:23:36 補充:

    If you means the length, that is [(5 1)^2 (6 6)^2]^0.5 (pyth theorem)=180^0.5=6X5^0.5 units範圍 means area in most cases

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