Home
Class 14
MATHS
On dividing the polynomial 8x^(3)-6x^(2)...

On dividing the polynomial `8x^(3)-6x^(2) + 10x + 3` by `(4x+1)`, the quotient is `2x^(2) +k`, where, k is equal to

A

`3-2x`

B

`-3+2x`

C

`3+2x`

D

`-3-2x`

Text Solution

AI Generated Solution

The correct Answer is:
To find the value of \( k \) in the polynomial division of \( 8x^3 - 6x^2 + 10x + 3 \) by \( 4x + 1 \) where the quotient is given as \( 2x^2 + k \), we can follow these steps: ### Step 1: Set up the polynomial division We need to divide \( 8x^3 - 6x^2 + 10x + 3 \) by \( 4x + 1 \). ### Step 2: Divide the leading terms Divide the leading term of the dividend \( 8x^3 \) by the leading term of the divisor \( 4x \): \[ \frac{8x^3}{4x} = 2x^2 \] This gives us the first term of the quotient. **Hint:** Always start polynomial long division by dividing the leading terms. ### Step 3: Multiply and subtract Now, multiply \( 2x^2 \) by the entire divisor \( 4x + 1 \): \[ 2x^2 \cdot (4x + 1) = 8x^3 + 2x^2 \] Subtract this from the original polynomial: \[ (8x^3 - 6x^2 + 10x + 3) - (8x^3 + 2x^2) = -8x^2 + 10x + 3 \] **Hint:** When subtracting, change the signs of the terms you are subtracting. ### Step 4: Repeat the process Now, take the new leading term \(-8x^2\) and divide it by \(4x\): \[ \frac{-8x^2}{4x} = -2x \] This gives us the next term of the quotient. **Hint:** Continue the process of dividing the leading terms until you reach a term that cannot be divided anymore. ### Step 5: Multiply and subtract again Multiply \(-2x\) by the divisor \(4x + 1\): \[ -2x \cdot (4x + 1) = -8x^2 - 2x \] Subtract this from \(-8x^2 + 10x + 3\): \[ (-8x^2 + 10x + 3) - (-8x^2 - 2x) = 12x + 3 \] **Hint:** Keep track of the signs carefully when performing subtraction. ### Step 6: Divide the last term Now, take \(12x\) and divide it by \(4x\): \[ \frac{12x}{4x} = 3 \] This gives us the last term of the quotient. **Hint:** The last term will be the constant term in the quotient. ### Step 7: Final multiplication and subtraction Multiply \(3\) by the divisor \(4x + 1\): \[ 3 \cdot (4x + 1) = 12x + 3 \] Subtract this from \(12x + 3\): \[ (12x + 3) - (12x + 3) = 0 \] **Hint:** If you reach zero, it means the division is complete with no remainder. ### Step 8: Write the complete quotient The complete quotient from the division is: \[ 2x^2 - 2x + 3 \] We know from the problem statement that this is equal to \(2x^2 + k\). ### Step 9: Solve for \( k \) Now, equate the two expressions: \[ 2x^2 - 2x + 3 = 2x^2 + k \] By comparing the constant terms, we find: \[ k = -2x + 3 \] Since \( k \) is a constant, we can conclude: \[ k = 3 \quad \text{(when } x = 0\text{)} \] ### Final Answer: Thus, the value of \( k \) is \( 3 \). ---
Promotional Banner

Topper's Solved these Questions

  • ALGEBRA

    BHARDWAJ ACADEMY|Exercise CHAPTER EXERCISE (Previous Years. Questions)|24 Videos
  • DATA HANDLING

    BHARDWAJ ACADEMY|Exercise CHAPTER EXERCISE (PREVIOUS YEARS QUESTIONS) |10 Videos
BHARDWAJ ACADEMY-ALGEBRA-CHAPTER EXERCISE (Previous Years. Questions)
  1. The sum of two positive numbes is 63. If one number x is double the ot...

    Text Solution

    |

  2. Sum of two numbers is 32. If one of them is -36, then the other number...

    Text Solution

    |

  3. A factor common to x^(2)+ 7x+10 and x^(2) -3x-10 is

    Text Solution

    |

  4. If (2)/(3) x = 0.6 and 0.02 y =1, then the value of x +y^(-1) is

    Text Solution

    |

  5. If y=f(x)=(x+2)/(x-1),x,y !=1 then x is equal to

    Text Solution

    |

  6. One factor of x^(4) +x^(2) +1 is

    Text Solution

    |

  7. The LCM of two prime numbers x and y, (x gt y) is 161 . The value ...

    Text Solution

    |

  8. Rani, who is y yr old at present, is x yr older than Hamid 15 yr ago, ...

    Text Solution

    |

  9. In the product (x^(2) -2) (1-3x+2x^(2)) the sum of coefficients of x^(...

    Text Solution

    |

  10. One of the factors of 4x^(2) + y^(2) + 14x-7y-4xy+12 is equal to

    Text Solution

    |

  11. If (3x-2)/(3) + (2x+3)/(2) = x +(7)/(6), then the value of (5x-2)/(4) ...

    Text Solution

    |

  12. If 4x^(2) + 12xy -8x+9y^(2) -12y = (ax+by) (ax+by-4), then the value o...

    Text Solution

    |

  13. In the product of (5x+2) and (2x^(2)-3x+5), the sum of the coefficient...

    Text Solution

    |

  14. If 3 (5x-7) -4 (8x-13) =2 (9x-11)-17, then the value of (7x-5)/(11x-9)...

    Text Solution

    |

  15. One of the factors of x^(4) + 4 is

    Text Solution

    |

  16. A common factor of x^(4) -256, x^(3)-4x^(2)+3x-12 and x^(2) -7x+12 ...

    Text Solution

    |

  17. On dividing the polynomial 8x^(3)-6x^(2) + 10x + 3 by (4x+1), the quot...

    Text Solution

    |

  18. In the product of (9x^(2) +15-x) and (-1-x+x^(2)), if A, B and C are t...

    Text Solution

    |

  19. When x = (1)/(9) and y = (-3)/(4), then the value of the expression 81...

    Text Solution

    |

  20. Abhi is twice as old as his dauther. Five years ago, his age was four ...

    Text Solution

    |