fibonacci_girl
rtex of the quadratic equation: y = 2x2 + 12x − 4.



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love_math
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rtex?

fibonacci_girl
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vertex

mathTalk
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2(x^2 + 6x2)=0
x^2+6x2=0
x = (6+(36+8)^(1/2) / 2
x= some complex

mathTalk
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what is a vertex ?

fibonacci_girl
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yes i need coordinates

love_math
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let the vertex=(x,y)

love_math
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then x=b/za, according to y=ax^2+bx+c

love_math
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x=b/2a

love_math
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so the answer is (3,22), do you understand?

mathTalk
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f'(x)=2(2x+6)=0
x = 3
y = 22
f''(x)=4 >0 hence local minimum
(3,22) ??

fibonacci_girl
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yes thanks

love_math
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yes ,the minimum is 22