SOLUTION: Prove that the value 2x^2-8x+9 cannot be less than 1

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Question 901424: Prove that the value 2x^2-8x+9 cannot be less than 1
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
y=2x%5E2-8x%2B9
Complete the square.
y=2%28x%5E2-4x%29%2B9
y=2%28x%5E2-4x%2B4%29%2B9-2%284%29
y=2%28x-2%29%5E2%2B9-8
y=2%28x-2%29%5E2%2B1
The parabola has a vertex at (2,1).
It opens upwards since 2%3E0 and its minimum value is y=1.
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graph%28300%2C300%2C-5%2C5%2C-5%2C5%2C2x%5E2-8x%2B9%29