SOLUTION: The 3 points (0,5), (1,3), (4,21) lie on a parabola and an inverse parabola. Find the two equations. I tired substituting in the points then using simultaneous equations to solv

Question 919974: The 3 points (0,5), (1,3), (4,21) lie on a parabola and an inverse parabola. Find the two equations.
I tired substituting in the points then using simultaneous equations to solve but it didn't work...
Found 2 solutions by Fombitz, Edwin McCravy:
Answer by Fombitz(32388) (Show Source): You can put this solution on YOUR website!
Parabola

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1.
1.
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2.
2.
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3.
3.
3.
From eq. 2,

Substituting,

Then,

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.

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Inverse parabola

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4.
4.
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5.
5.
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6.
6.
Subtract eq. 5 from eq. 4 and eq. 6 to eliminate
7.
7.
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8.
8.
8.
Multiply eq. 7 by -3 and add to eq. 8 to eliminate

Then,

Finally,

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.
.

Answer by Edwin McCravy(20055) (Show Source): You can put this solution on YOUR website!
Fombitz beat me to it. I always like to show graphs, and
the tutors that just show the algebra and no graphs usually
beat me to it because I have to do the algebra first and
then do the graphs. Anyway here's the graph:

Edwin
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