Answer:
f(x) = x^3 -2x^2 -3x +7
Step-by-step explanation:
Cubic polynomial regression using your favorite tool (graphing calculator, spreadsheet, or web site) will tell you the interpolating polynomial is ...
f(x) = x^3 -2x^2 -3x +7
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You can use Lagrange polynomial interpolation. It gives the function as the sum of four factored cubics:
Or, you can write equations for the coefficients a, b, c, d of ...
ax^3 +bx^2 +cx +d = f(x)
These would be ...
a + b + c + d = 3
8a +4b +2c +d = 1
27a +9b +3c +d = 7
64a +16b +4c +d = 27
Your friendly linear equation solver will tell you ...
(a, b, c, d) = (1, -2, -3, 7) . . . matches the equation shown above
