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y = - 2 {(x + 3) }^(2) - 4Can you please answer this. It is graphing quadratics in vertex form

y = - 2 {(x + 3) }^(2) - 4Can you please answer this. It is graphing quadratics in-example-1
User Sinwav
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1 Answer

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19 votes

The equation in the vertex form is expressed as

y = - 2(x - 4)^2 + 2

The equation of a parabola in the vertex form is expressed as

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

where

h and k are the vertices of the parabola. By comparing both equations,

a = - 2

h = 4, k = 2

Thus, vertex = (4, 2)

The next step is to find the y intercept. The value of y when x = 0. Thus,

y = - 2(0 - 4)^2 + 2

y = - 2(- 4)^2 + 2 = - 32 + 2

y intercept = - 30

The next step is to find the x intercept. The value of x when y = 0. Thus,

0 = - 2(x - 4)^2 + 2

0 = - 2(x^2 - 8x + 16) + 2

0 = - 2x^2 + 16x - 32 + 2

0 = - 2x^2 + 16x - 30

0 = - 2x^2 + 10x + 6x - 30

0 = - 2x(x - 5) + 6(x - 5)

(x - 5)(- 2x + 6) = 0

x - 5 = 0 or - 2x + 6 = 0

x = 5 or 2x = 6

x = 5 or x = 6/2 = 3

Thus, we would graph the parabola using the above points. the graph is shown below

y = - 2 {(x + 3) }^(2) - 4Can you please answer this. It is graphing quadratics in-example-1
User Fabio Nolasco
by
2.6k points
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