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If the polynomials az^3+ 4z^2+ 3z-4 and ...

If the polynomials `az^3+ 4z^2+ 3z-4 and z^3-4z+ a` leave the same remainder when divided by z-3, the value of a is

A

`-1`

B

0

C

1

D

2

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the value of \( a \) such that the two polynomials \( P_1(z) = az^3 + 4z^2 + 3z - 4 \) and \( P_2(z) = z^3 - 4z + a \) leave the same remainder when divided by \( z - 3 \). ### Step-by-Step Solution: 1. **Identify the Polynomials**: - Let \( P_1(z) = az^3 + 4z^2 + 3z - 4 \) - Let \( P_2(z) = z^3 - 4z + a \) 2. **Use the Remainder Theorem**: - According to the Remainder Theorem, the remainder of a polynomial \( P(z) \) when divided by \( z - c \) is \( P(c) \). - We will find \( P_1(3) \) and \( P_2(3) \). 3. **Calculate \( P_1(3) \)**: \[ P_1(3) = a(3^3) + 4(3^2) + 3(3) - 4 \] \[ = a(27) + 4(9) + 9 - 4 \] \[ = 27a + 36 + 9 - 4 \] \[ = 27a + 41 \] 4. **Calculate \( P_2(3) \)**: \[ P_2(3) = (3^3) - 4(3) + a \] \[ = 27 - 12 + a \] \[ = 15 + a \] 5. **Set the Remainders Equal**: Since both polynomials leave the same remainder when divided by \( z - 3 \), we set the two expressions equal: \[ 27a + 41 = 15 + a \] 6. **Solve for \( a \)**: - Rearranging the equation: \[ 27a - a = 15 - 41 \] \[ 26a = -26 \] \[ a = -1 \] ### Final Answer: The value of \( a \) is \( -1 \).
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