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Quadratic function with (-2,4) as the vertex and passes through (-4,-4)

2 Answers

13 votes
-2x^2 + 8 because if you turn it into vertex form and determine
User Madarco
by
4.6k points
9 votes

Answer:


f(x)=-2x^2-8x-4

Explanation:

Vertex form of quadratic function:
f(x)=a(x-h)^2+k

where
(h,k) is the vertex

Given:

  • vertex = (-2, 4)


\implies f(x)=a(x+2)^2+4

Given:

  • point on curve = (-4, -4)


\implies f(-4)=-4\\\\\implies a(-4+2)^2+4=-4\\\\\implies a(-2)^2=-4-4\\\\\implies 4a=-8\\\\\implies a = -2

Therefore,


f(x)=-2(x+2)^2+4\\\\\implies f(x)=-2(x^2+4x+4)+4\\\\\implies f(x)=-2x^2-8x-8+4\\\\\implies f(x)=-2x^2-8x-4

User Justin Reeves
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4.7k points