Home
Class 10
MATHS
Using the Remainder Theorem find the rem...

Using the Remainder Theorem find the remainders obtained when `x^(3)+(kx+8)x+k` is divided by `x-1andx-2`.
Hence find k if the sum of the remainders is 1.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem using the Remainder Theorem, we will follow these steps: ### Step 1: Define the polynomial Let \( P(x) = x^3 + (kx + 8)x + k \). We can rewrite this as: \[ P(x) = x^3 + kx^2 + 8x + k \] ### Step 2: Find the remainder when divided by \( x - 1 \) According to the Remainder Theorem, the remainder \( r_1 \) when \( P(x) \) is divided by \( x - 1 \) is given by \( P(1) \): \[ P(1) = 1^3 + k(1^2) + 8(1) + k = 1 + k + 8 + k = 2k + 9 \] So, \( r_1 = 2k + 9 \). ### Step 3: Find the remainder when divided by \( x - 2 \) Similarly, the remainder \( r_2 \) when \( P(x) \) is divided by \( x - 2 \) is given by \( P(2) \): \[ P(2) = 2^3 + k(2^2) + 8(2) + k = 8 + 4k + 16 + k = 5k + 24 \] So, \( r_2 = 5k + 24 \). ### Step 4: Set up the equation for the sum of the remainders According to the problem, the sum of the remainders is given to be 1: \[ r_1 + r_2 = 1 \] Substituting the values of \( r_1 \) and \( r_2 \): \[ (2k + 9) + (5k + 24) = 1 \] This simplifies to: \[ 7k + 33 = 1 \] ### Step 5: Solve for \( k \) Now, we will solve for \( k \): \[ 7k = 1 - 33 \] \[ 7k = -32 \] \[ k = -\frac{32}{7} \] ### Final Answer Thus, the value of \( k \) is: \[ k = -\frac{32}{7} \]
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

Similar Questions

Explore conceptually related problems

Using the Remainder Theorem find the remainders obtained when x^(3)+(kx+8)x +k is divided by x + 1 and x - 2. Hence, find k if the sum of the two remainders is 1.

Find the remainder when p(x)=4x^3-12 x^2+14 x-3 is divided by g(x)=x-1/2

Knowledge Check

  • Using remainder theorem, find the remainder when 3x^(4) - 4x^(3) - 3x - 1 is divided by (x - 1).

    A
    1
    B
    -5
    C
    5
    D
    -1
  • The remainder obtained when 3x^(4)+7x^(3)+8x^(2)-2x-3 is divided by x+1 iss

    A
    `-3`
    B
    0
    C
    3
    D
    5
  • Find the remainder when 2 x^(3) - 7 x ^(2) + 5 x - 9 is divided by 2 x - 3

    A
    `-(21)/(2)`
    B
    `-(21)/(4)`
    C
    `-(129)/(4)`
    D
    `-(129)/(2)`
  • Similar Questions

    Explore conceptually related problems

    Find the remainder when p(x)=4x^3-12 x^2+14 x-3 is divided by g(x)=x-1/2

    Find the remainder when p(x)=x^3-a x^2+6x-a is divided by (x-a)dot

    Find the remainder when p(x)=x^3-a x^2+6x-a is divided by (x-a)dot

    Find the remainder when x^3-a x^2+6x-a is divided by x-a .

    Find the remainder when x^(3)-ax^(2)+6x-a is divided by x - a