SOLUTION: y=-2x^2

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Question 173351: y=-2x^2
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Do you want to graph this? Please post full instructions.




Table of Contents:


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In order to graph y=-2x%5E2, we need to plot some points.


Let's find y when x=-2
(Note: you can start with any x-value):


y=-2x%5E2 Start with the given equation.


y=-2%28-2%29%5E2 Plug in x=-2.


y=-2%284%29 Square -2 to get 4.


y=-8 Multiply -2 and 4 to get -8.


So when x=-2, then y=-8.


So we have the point .


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Let's find y when x=-1:


y=-2x%5E2 Start with the given equation.


y=-2%28-1%29%5E2 Plug in x=-1.


y=-2%281%29 Square -1 to get 1.


y=-2 Multiply -2 and 1 to get -2.


So when x=-1, then y=-2.


So we have the point .


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Let's find y when x=0:


y=-2x%5E2 Start with the given equation.


y=-2%280%29%5E2 Plug in x=0.


y=-2%280%29 Square 0 to get 0.


y=0 Multiply -2 and 0 to get 0.


So when x=0, then y=0.


So we have the point .


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Let's find y when x=1:


y=-2x%5E2 Start with the given equation.


y=-2%281%29%5E2 Plug in x=1.


y=-2%281%29 Square 1 to get 1.


y=-2 Multiply -2 and 1 to get -2.


So when x=1, then y=-2.


So we have the point .


----------------------------------------------------


Let's find y when x=2:


y=-2x%5E2 Start with the given equation.


y=-2%282%29%5E2 Plug in x=2.


y=-2%284%29 Square 2 to get 4.


y=-8 Multiply -2 and 4 to get -8.


So when x=2, then y=-8.


So we have the point .


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Now let's make a table of the values we just found.


Table of Values:





xy
-2-8


-1-2


00


1-2


2-8



Now let's plot the points:







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Graph:


Now draw a curve through all of the points to graph y=-2x%5E2:


Graph of y=-2x%5E2