150k views
3 votes
Equation of the polynomial described below. Degree 4. Root of multiplicity 2 at x=4, and a root of multiplicity 1 at x=1 and x=-2. Y-intercept at (0, -3).

Options:
A) f(x)=(x−4)
2
(x−1)(x+2)
B) f(x)=(x+4)
2
(x−1)(x+2)
C) f(x)=(x−4)(x−1)(x+2)
D) f(x)=(x−4)(x−1)
2
(x+2)

User Osagie
by
8.1k points

1 Answer

3 votes

Final answer:

None of the provided options (A, B, C, or D) for the polynomial equation with the specified roots and y-intercept is correct. The polynomial with roots of multiplicity 2 at x=4, and a root of multiplicity 1 at x=1 and x=-2, with a y-intercept at (0, -3), should yield -3 when x=0. None of the options provided satisfy this condition, indicating a possible error in the options or the constraints provided.

Step-by-step explanation:

The student is looking for the equation of a polynomial of degree 4 with given roots and a specific y-intercept. Given the information about roots and y-intercept, we can construct the polynomial function. The root of multiplicity 2 at x=4 is represented as (x-4)^2, the single root at x=1 as (x-1), and the single root at x=-2 as (x+2). Finally, to respect the y-intercept at (0, -3), the polynomial equation must give -3 when x=0. Only one of the provided options will satisfy the y-intercept condition. Now, we plug in x=0 into each option and find the correct polynomial that yields -3.

For Option A: f(x)=(x-4)^2(x-1)(x+2), when x=0, f(0)=(-4)^2(-1)(2) = 16(-1)(2) = -32, which is not equal to -3.

Option B: f(x)=(x+4)^2(x-1)(x+2) is incorrect because the root should be at x=4, not -4.

Option C: f(x)=(x-4)(x-1)(x+2) does not have the root at x=4 with the correct multiplicity.

Option D: f(x)=(x-4)(x-1)^2(x+2), when x=0, f(0)=(-4)(-1)^2(2) = -8, which is also not equal to -3.

Therefore, none of the provided options are correct, and the student should be informed that they might need to recheck their options or the constraints given for the polynomial.

User Rich Linnell
by
8.1k points