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2 votes
Vertex of y= 2x^2+8 +1​

2 Answers

3 votes
(-2,-7) is the vertex but it seems you missed an X
User Nesrin
by
5.0k points
4 votes

Answer:

(-2,-7) is the vertex if you meant to write y=2x^2+8x+1

Step-by-step explanation:

I think you missed an x next to 8

y=2x^2+8x+1

First step factor 2x^2+8x so that we get 1 directly in front of x^2

y=2(1x^2+4x) +1

y=2( x^2+4x ) +1 Now I will leave a space for completing the square

y=2( x^2+4x+(4/2)^2)+1-2(4/2)^2 Whatever you add in you must subtract out

y=2( x^2+4x+2^2)+1-2(2^2)

y=2( x+2)^2 +1 -2(4)

y=2( x+2)^2 +1-8

y=2( x+2)^2 -7

Vertex is (-2,-7)

Or You could find -b/(2a) then plug in that into y=f(x) to find the y-coodinate

So -b/(2a)=-8/(2*2)=-8/4=-2

2(-2)^2+8(-2)+1=8-16+1=-8+1=-7

So the vertex is (-2,-7)

User DSoa
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4.9k points