SOLUTION: What is the minimum value of x^2-8x.

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Question 1104330: What is the minimum value of x^2-8x.
Found 2 solutions by josgarithmetic, josmiceli:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2-8x
x%28x-8%29
Roots at 0 and 8.

Minimum is at the middle of 0 and 8; which is at 4.

Evaluate for x=4.
4%5E2-8%2A4
16-32
highlight%28-16%29---------Minimum

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+x%5E2+-+8x+
+x%5Bmin%5D+=+-b%2F%282a%29+
+x%5Bmin%5D+=+%28-%28-8%29%29%2F%28+2%2A1%29+
+x%5Bmin%5D+=+4+
+y%5Bmin%5D+=+4%5E2+-+8%2A4+
+y%5Bmin%5D+=+16+-+32+
+y%5Bmin%5D+=+-16+
the minimum value is -16
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Here's the plot:
+graph%28+400%2C+400%2C+-10%2C+10%2C+-20%2C+10%2C+x%5E2+-+8x%29+