# Upside-down Parabola

Discussion in 'Off-Topic Chat' started by nycmathguy, Aug 4, 2022.

1. ### nycmathguy

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I know that placing a minus sign in front of x^2 for y = x^2 forms an upside-down U on the xy-place. Why does this happen? Why does a minus invert the parabola on the xy-plane?

nycmathguy, Aug 4, 2022

2. ### MathLover1

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y = -x^2

make table:
x|y
-2|-4....................y = -(-2)^2=-4
-1|-1....................y = -(-1)^2=-1
0|0....................y = -(0)^2=0
1|-1....................y = -(1)^2=-1
2|-4....................y = -(2)^2=-4

make conclusion why parabola is upside-down

MathLover1, Aug 4, 2022
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3. ### nycmathguy

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Based on the table the parabola is upside-down because the x-and y-coordinates change signs. Yes?

nycmathguy, Aug 4, 2022
4. ### MathLover1

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because the y-coordinates are all negative

MathLover1, Aug 4, 2022
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