The vertex of this parabola is at (-5, -2). When the x-value is -4, the y value is 2. What is the coefficient of the squared expressio

Question

The vertex of this parabola is at (-5, -2). When the x-value is -4, the
y value is 2. What is the coefficient of the squared expression in the
parabola’s equation?
(-5,-2)
© A. 1
O B. -1
C. 5
D. 4

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Thành Đạt 4 years 2021-08-22T04:56:02+00:00 1 Answers 103 views 0

Answers ( )

  1. Jezebel
    0
    2021-08-22T04:57:58+00:00
    Reply

    Answer: D. 4

    So you know the vertex is at (-5,-2) and there is a point (-4,2). This means you can write it in vertex form.

    Vertex form is y= a(x-h)^2 +k
    Therefore:
    y= a(x+5)^2 -2

    Now since you know that plug in the point to find a.

    2 = a(-4+5)^2-2
    4 = a

    So your equation is:
    y= 4(x+5)^2 -2

    Now you want to know the coefficient of the squared expression. So let’s multiply it out.

    y= 4 [(x+5)(x+5)]-2
    y= 4(x^2+10x+25)-2
    y= 4x^2+40x+100-2
    y= 4x^2 + 40x + 98

    Therefore your coefficient is 4.

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )