Which polynomial function has x intercepts -1, 0, and 2 and passes through the point (1, -6)?
f(x) = x3 - x2 - 2x
f(x) = 3x3 - 3x2 - 6x
f(x) = x3 + x2 - 2x
f(x) = 3x3 + 3x2 - 6x
Solution:
We know that the equation of a polynomial function with x-intercepts as -1, 0, 2 is
f(x) = a(x - (x - 1))(x - 0)(x - 2)
= a[x(x + 1)(x - 2)]
= a(x3 - x2 - 2x)
It passes through the point (1, -6)
⇒ a(13 - 12 - 2(1)) = -6
⇒ a (1 - 1 - 2) = -6
⇒ -2a = -6
Divide both sides by -2
⇒ a = 3
So we get,
f(x) = 3(x3 - x2 - 2x) = 3x3 - 3x2 - 6x
Therefore, the polynomial function which has x intercepts -1, 0, and 2 and passes through the point (1, -6) is f(x) = 3x3 - 3x2 - 6x.
Which polynomial function has x intercepts -1, 0, and 2 and passes through the point (1, -6)?
Summary:
The polynomial function which has x intercepts -1, 0, and 2 and passes through the point (1, -6) is f(x) = 3x3 - 3x2 - 6x.
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