Question

the vertex of this parabola is at (3,-2). When the x-vaue is 4, the y-value is 3. What is the coefficient of the squared expression in the parabola equation?

Answer 1

Answer:   5

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Explanation:

Vertex form is

y = a(x-h)^2 + k

We are told the vertex is (3,-2), so we know (h,k) = (3,-2)

y = a(x-h)^2 + k will update to y = a(x-3)^2 - 2

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Then we also know that (x,y) = (4,3) is a point on the parabola. Plug those x and y values into the equation and solve for 'a'

y = a(x-3)^2 - 2

3 = a(4-3)^2 - 2

3 = a(1)^2 - 2

3 = a - 2

3+2 = a

5 = a

a = 5

This is the coefficient of the x^2 term since the standard form is y = ax^2+bx+c.