Let f(x) = ax^2+bx+c.
If (0, 1) and (1, 1) and (-1, 3) lie on the graph of the function, then, what are the values of a, b and c? Show the three calculations and draw the graphic of the function.
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f(0) = 1 --> c=1
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f(1) = 1 --> a + b + 1 = 1
a + b = 0
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f(-1) = 3 --> a - b + 1 = 3
a - b = 2
a + b = 0
----------- Add
2a = 2
a = 1
b = -1
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f(x) = x^2 - x + 1
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Or do it like this:
|y x^2 x 1|
|0 1 1 1|
|1 1 1 1| = 0
|3 1 -1 1|
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dl the FREE graph software at
www.padowan.dk
to graph it.