Home
Class 12
MATHS
Find n in the binomial (2^(1/3)+1/(3^(1/...

Find `n` in the binomial `(2^(1/3)+1/(3^(1/3)))^n` , if the ration 7th term from the beginning to the 7 term from the end `1/6dot`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to find the value of \( n \) in the binomial expression \( (2^{1/3} + 3^{-1/3})^n \), given that the ratio of the 7th term from the beginning to the 7th term from the end is \( \frac{1}{6} \). ### Step-by-Step Solution: 1. **Identify the General Term**: The general term \( T_r \) in the binomial expansion of \( (a + b)^n \) is given by: \[ T_r = \binom{n}{r} a^{n-r} b^r \] For our case, \( a = 2^{1/3} \) and \( b = 3^{-1/3} \). 2. **Find the 7th Term from the Beginning**: The 7th term from the beginning corresponds to \( r = 6 \): \[ T_7 = \binom{n}{6} (2^{1/3})^{n-6} (3^{-1/3})^6 \] Simplifying this, we get: \[ T_7 = \binom{n}{6} \cdot 2^{(n-6)/3} \cdot 3^{-2} \] 3. **Find the 7th Term from the End**: The 7th term from the end corresponds to \( r = n - 6 \): \[ T_{n-5} = \binom{n}{n-6} (2^{1/3})^{6} (3^{-1/3})^{n-6} \] Simplifying this, we get: \[ T_{n-5} = \binom{n}{6} \cdot 2^{2} \cdot 3^{-(n-6)/3} \] 4. **Set Up the Ratio**: According to the problem, the ratio of the 7th term from the beginning to the 7th term from the end is: \[ \frac{T_7}{T_{n-5}} = \frac{1}{6} \] Plugging in the expressions we derived: \[ \frac{\binom{n}{6} \cdot 2^{(n-6)/3} \cdot 3^{-2}}{\binom{n}{6} \cdot 2^{2} \cdot 3^{-(n-6)/3}} = \frac{1}{6} \] 5. **Cancel Common Terms**: The \( \binom{n}{6} \) cancels out: \[ \frac{2^{(n-6)/3} \cdot 3^{-2}}{2^{2} \cdot 3^{-(n-6)/3}} = \frac{1}{6} \] 6. **Simplify the Equation**: Rearranging gives: \[ 2^{(n-6)/3 - 2} \cdot 3^{(n-6)/3 - 2} = \frac{1}{6} \] This can be rewritten as: \[ 6^{(n-12)/3} = \frac{1}{6} \] 7. **Equate the Exponents**: Since \( \frac{1}{6} = 6^{-1} \), we have: \[ \frac{n-12}{3} = -1 \] Multiplying through by 3 gives: \[ n - 12 = -3 \] Therefore: \[ n = 9 \] ### Final Answer: The value of \( n \) is \( 9 \).

To solve the problem, we need to find the value of \( n \) in the binomial expression \( (2^{1/3} + 3^{-1/3})^n \), given that the ratio of the 7th term from the beginning to the 7th term from the end is \( \frac{1}{6} \). ### Step-by-Step Solution: 1. **Identify the General Term**: The general term \( T_r \) in the binomial expansion of \( (a + b)^n \) is given by: \[ T_r = \binom{n}{r} a^{n-r} b^r ...
Promotional Banner

Topper's Solved these Questions

  • BINOMIAL THEOREM

    CENGAGE ENGLISH|Exercise Concept Application Exercise 8.2|10 Videos
  • BINOMIAL THEOREM

    CENGAGE ENGLISH|Exercise Concept Application Exercise 8.3|7 Videos
  • BINOMIAL THEOREM

    CENGAGE ENGLISH|Exercise Example|10 Videos
  • AREA

    CENGAGE ENGLISH|Exercise Comprehension Type|2 Videos
  • CIRCLE

    CENGAGE ENGLISH|Exercise MATRIX MATCH TYPE|7 Videos

Similar Questions

Explore conceptually related problems

In (3 3+1/(3 3))^n if the ratio of 7th term from the beginning to the 7th term from the end is 1/6, then find the value of ndot

In ( 2^(1/3)+1/3^(1/ 3))^n if the ratio of 7th term from the beginning to the 7th term from the end is 1/6, then find the value of ndot

In (2^(1/3)+1/(3^(1/3)))^n if the ratio of 7th term from the beginning to the 7th term from the end is 1/6 , then the value of n is (a) 6 (b) 9 (c) 12 (d) 15

In the expansion of (2^(1/3) +1/(2(3)^(1/3)))^10 then the ratio of 5th term from beginning and 5th term from end is equal to (A) 6^(1/3):1 (B) 4(36)^(1/3):1 (C) 2(36)^(1/3):1 (D) 4(36)^(1/3):1

Find n, if the ratio of the fifth term from the beginning to the fifth term from the end in the expansion of (root(4)2+1/(root(4)3))^n is sqrt(6):1

Find n , if the ratio of the fifth term from the beginning to the fifth term from the end in the expansion of (root(4)2 +1/(root(4)3 ))^n is sqrt(6): 1.

Find the 4th term from the beginning and 4^(th) term from the end in the expansion of (x+2/x)^9

Find the sixth term of the expansion of (y^(1//2) + x^(1//3) )^(n) , if the binomial coefficient of the third term from the end is 45 .

Find the sixth term in the expansion (y^(1/2)+x^(1/3))^n , if the binomial coefficient of the third term of the end is 45.

Find the sixth term in the expansion (y^(1/2)+x^(1/3))^n , if the binomial coefficient of the third term of the end is 45.

CENGAGE ENGLISH-BINOMIAL THEOREM-Concept Application Exercise 8.1
  1. The first three terms in the expansion of (1+a x)^n(n!=0) are 1,6xa n ...

    Text Solution

    |

  2. If the coefficient of 4th term in the expansion of (a+b)^n is 56, then...

    Text Solution

    |

  3. The two successive terms in the expansion of (1+x)^24 whose coefficie...

    Text Solution

    |

  4. If the number of terms in the expansion of (x+y+z)^n are 36, then find...

    Text Solution

    |

  5. Find the value of 1/(81^n)-((10)/(81^n))^(2n)C1+((10^2)/(81^n))^(2n)C2...

    Text Solution

    |

  6. sum(r=0)^n(-1)^r^n Cr[1/(2^r)+3/(2^(2r))+7/(2^(3r))+(15)/(2^(4r))+ u p...

    Text Solution

    |

  7. Find n in the binomial (2^(1/3)+1/(3^(1/3)))^n , if the ration 7th ter...

    Text Solution

    |

  8. If the coefficients of (r-5)^(t h) and (2r-1)^(t h) terms in the expan...

    Text Solution

    |

  9. Find the number of irrational terms in the expansion of (5^(1//6)+2^(1...

    Text Solution

    |

  10. Represent cos 6 theta in terms of cos theta.

    Text Solution

    |

  11. Find the number of nonzero terms in the expansion of (1+3sqrt(2)x)^9+(...

    Text Solution

    |

  12. Find the value of (sqrt(2)+1)^6-(sqrt(2)-1)^6dot

    Text Solution

    |

  13. Find the degree of the polynomial 1/(sqrt(4x+1)){((1+sqrt(4x+1))/2)^7-...

    Text Solution

    |

  14. Let R=(5sqrt(5)+11)^(2n+1)a n df=R-[R]w h e r e[] denotes the greatest...

    Text Solution

    |

  15. If the middle term in the binomial expansion of (1/x+xsinx)^(10) is eq...

    Text Solution

    |

  16. Find the middle term in the expansion of (x^2+1/(x^2)+2)^ndot

    Text Solution

    |

  17. If the number of terms in the expansion (1+2x-3y+4z)^(n) is 286, then...

    Text Solution

    |