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If x

^5 + ax2 + b is divided by x
^2 − 5x + 6, the remainder is (x + 1), then
find the value of the unknown coefficients a and b.

User Shaun Chua
by
8.3k points

1 Answer

4 votes

Answer:

Im not sure about what I'm doing but I hope its correct.

Explanation:

To find the values of the unknown coefficients a and b, we can use the remainder theorem. According to the theorem, when a polynomial f(x) is divided by (x - c), the remainder is equal to f(c).

Given:

Polynomial: x^5 + ax^2 + b

Divisor: x^2 - 5x + 6

Remainder: x + 1

Using the remainder theorem, we can equate the remainder to the polynomial evaluated at the root of the divisor, which is x = -1.

Substituting x = -1 into the polynomial:

(-1)^5 + a(-1)^2 + b = -1 + 1

Simplifying:

-1 + a + b = 0

This equation represents one relationship between a and b.

Additionally, we can also divide the polynomial by the divisor to find the quotient:

(x^5 + ax^2 + b) / (x^2 - 5x + 6) = Q(x) + (x + 1)

We can perform long division or synthetic division to find the quotient Q(x), which will be a polynomial without any remainder. The remainder in this case is (x + 1).

Using long division:

x^3 + 5x^2 + (21a + 36)x + (36a + b - 6)

_______________________________________________________

x^2 - 5x + 6 | x^5 + 0x^4 + ax^2 + 0x^3 + b + 0x

The quotient is x^3 + 5x^2 + (21a + 36)x + (36a + b - 6).

From this, we can see that the coefficient of x in the remainder (x + 1) is (21a + 36), and the constant term in the remainder is (36a + b - 6).

Therefore, we have two equations:

-1 + a + b = 0 (from the remainder theorem)

21a + 36 = 1 (from the coefficient of x in the remainder)

36a + b - 6 = 0 (from the constant term in the remainder)

By solving these equations simultaneously, we can find the values of a and b.

User Wbartussek
by
7.0k points