SOLUTION: I need to find the intercepts, graph and check for symmetry. y=4-x^2, could someone show me step by step?

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Question 100246: I need to find the intercepts, graph and check for symmetry. y=4-x^2, could someone show me step by step?
Answer by tutorcecilia(2152) About Me  (Show Source):
You can put this solution on YOUR website!

Re-write the polynomial:
y=-x^2+4 [the slope is negative, so the parabola will open downwards]
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To find the line of symetry, use the formula for finding the x-value of the vertex: -b/2a
Let y=-x^2+0x+4
Let a=-1
Let b=0
Let c=4
So, -b/2a=-(0)/(2)(-1)=0/-2=0
Therefore, the line of symetry is located at x=0 or the y-axis.
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To find the x-intercepts, plug the values into the quadratic formula and solve:
Let y=-x^2+0x+4
The result is x=-2 or x=2
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Graphing:
+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+-x%5E2%2B4%29+