Home
Class 12
MATHS
If C(0),C(1),C(2),C(3), . . .,C(n) be bi...

If `C_(0),C_(1),C_(2),C_(3), . . .,C_(n)` be binomial coefficients in the expansion of `(1+x)^(n)`, then
Q. The value of the expression `C_(0)-2C_(1)+3C_(2)-. . . .+(-1)^(n)(n+1)C_(n)` is equal to

A

0

B

`2^(n)(n+3)`

C

`2^(n-1)(n-2)`

D

None of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the expression \( C_0 - 2C_1 + 3C_2 - \ldots + (-1)^n (n+1)C_n \), where \( C_r = \binom{n}{r} \) are the binomial coefficients from the expansion of \( (1+x)^n \), we can follow these steps: ### Step 1: Rewrite the expression We can express the given sum in a more manageable form: \[ S_n = \sum_{r=0}^{n} (-1)^r (r+1) C_r \] This can be separated into two sums: \[ S_n = \sum_{r=0}^{n} (-1)^r C_r + \sum_{r=0}^{n} (-1)^r r C_r \] ### Step 2: Evaluate the first sum The first sum \( \sum_{r=0}^{n} (-1)^r C_r \) can be evaluated using the Binomial Theorem: \[ \sum_{r=0}^{n} (-1)^r \binom{n}{r} = (1-1)^n = 0 \] ### Step 3: Evaluate the second sum For the second sum \( \sum_{r=0}^{n} (-1)^r r C_r \), we can use the identity \( r C_r = n C_{r-1} \): \[ \sum_{r=0}^{n} (-1)^r r C_r = n \sum_{r=1}^{n} (-1)^r C_{r-1} \] Changing the index of summation: \[ = n \sum_{s=0}^{n-1} (-1)^{s+1} C_s = -n \sum_{s=0}^{n-1} (-1)^s C_s \] Using the result from Step 2: \[ \sum_{s=0}^{n-1} (-1)^s C_s = (1-1)^{n-1} = 0 \] ### Step 4: Combine the results Now we combine the results from both sums: \[ S_n = 0 - n \cdot 0 = 0 \] ### Final Answer Thus, the value of the expression \( C_0 - 2C_1 + 3C_2 - \ldots + (-1)^n (n+1)C_n \) is: \[ \boxed{0} \]
Promotional Banner

Topper's Solved these Questions

  • BINOMIAL THEOREM

    AAKASH INSTITUTE ENGLISH|Exercise Assignment (section-E) Objective type question (Assertion-Reson Type Questions)|6 Videos
  • BINOMIAL THEOREM

    AAKASH INSTITUTE ENGLISH|Exercise Assignment (section-G) Objective type question (Integer Answer Type Questions)|1 Videos
  • BINOMIAL THEOREM

    AAKASH INSTITUTE ENGLISH|Exercise Assignment (section-C) Objective type question (More than one correct answer)|15 Videos
  • APPLICATION OF INTEGRALS

    AAKASH INSTITUTE ENGLISH|Exercise Assignment Section - I Aakash Challengers Questions|2 Videos
  • COMPLEX NUMBERS AND QUADRATIC EQUATIONS

    AAKASH INSTITUTE ENGLISH|Exercise section-J (Aakash Challengers Qestions)|13 Videos

Similar Questions

Explore conceptually related problems

If C_(0),C_(1),C_(2),C_(3), . . .,C_(n) be binomial coefficients in the expansion of (1+x)^(n) , then Q. The value of the expression C_(0)+2C_(1) +3C_(2)+. . . .+(n+1)C_(n) is equal to

If C_(0), C_(1), C_(2),..., C_(n) are binomial coefficients in the expansion of (1 + x)^(n), then the value of C_(0) + (C_(1))/(2) + (C_(2))/(3) + (C_(3))/(4) +...+ (C_(n))/(n+1) is

If C_(0), C_(1), C_(2),..., C_(n) denote the binomial coefficients in the expansion of (1 + x)^(n) , then . 1. C_(1) - 2 . C_(2) + 3.C_(3) - 4. C_(4) + ...+ (-1)^(n-1) nC_(n)=

If C_(0), C_(1), C_(2),...,C_(n) denote the binomial coefficients in the expansion of (1 + x)^n) , then xC_(0)-(x -1) C_(1)+(x-2)C_(2)-(x -3)C_(3)+...+(-1)^(n) (x -n) C_(n)=

If C_(0),C_(1), C_(2),...,C_(N) denote the binomial coefficients in the expansion of (1 + x)^(n) , then 1^(3). C_(1)-2^(3). C_(3) - 4^(3) . C_(4) + ...+ (-1)^(n-1)n^(3) C_(n)=

If C_(0), C_(1), C_(2), …, C_(n) denote the binomial coefficients in the expansion of (1 + x)^(n) , then sum_(0 ler )^(n)sum_(lt s len)^(n)C_(r)C_(s) =.

If C_(0), C_(1), C_(2),…, C_(n) denote the binomial coefficients in the expansion of (1 + x)^(n) , then sum_(r=0)^(n)sum_(s=0)^(n)(C_(r) +C_(s))

If C_(0), C_(1), C_(2), …, C_(n) denote the binomial coefficients in the expansion of (1 + x)^(n) , then sum_(r=0)^(n)sum_(s=0)^(n)C_(r)C_(s) =

If C_(0), C_(1), C_(2), ..., C_(n) denote the binomial cefficients in the expansion of (1 + x )^(n) , then a C_(0) + (a + b) C_(1) + (a + 2b) C_(2) + ...+ (a + nb)C_(n) = .

If C_(0), C_(1), C_(2), ..., C_(n) denote the binomial cefficients in the expansion of (1 + x )^(n) , then a C_(0) + (a + b) C_(1) + (a + 2b) C_(2) + ...+ (a + nb)C_(n) = .