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Find the equation of the parabola that goes through the three points (0, 9), (1, 7) and (2, 7).

 Sep 23, 2020
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Find the equation of the parabola that goes through the three points (0, 9), (1, 7) and (2, 7).

 

Hello Guest!

 

\(y=ax^2+bx+c\)

 

Put the coordinates of the three points in
the equation \(y=ax^2+bx+c\), and solve for a, b, and c.

 

I.    \(9=c\)

II.   \(7=a+b+9\)

III.  \(7=4a+2b+9\)

 

4 * II  .     \(28=4a+4b+36\)

  - III.         \(\underline{7=4a+2b+9}\)

                21  =           2b  + 27 

\(2b=21-27=-6\)

\(b=-3\)

\(7=a+b+9\)

\(7=a-3+9\)

\(a=1\)

 

The general equation  \(y=ax^2+bx+c\)

becomes the real equation \(y=x^2-3x+9\).

laugh  !

 Sep 23, 2020

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