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If (1+x)^(n) = C(0) + C(1)x + C(2)x^(2) ...

If `(1+x)^(n) = C_(0) + C_(1)x + C_(2)x^(2) + "….." + C_(n)x^(n)`, then `C_(0) - (C_(0) + C_(1)) +(C_(0) + C_(1) + C_(2)) - (C_(0) + C_(1) + C_(2) + C_(3))+ "….."` `(-1)^(n-1) (C_(0) + C_(1) + "……" + C_(n-1))` is (where n is even integer and `C_(r) = .^(n)C_(r)`)

A

a positive value

B

a negative value

C

divisible by `2^(n-1)`

D

divisible by `2^(n)`

Text Solution

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The correct Answer is:
To solve the given problem, we start with the binomial expansion of \((1+x)^n\): \[ (1+x)^n = C_0 + C_1 x + C_2 x^2 + \ldots + C_n x^n \] where \(C_r = \binom{n}{r}\). We need to evaluate the expression: \[ C_0 - (C_0 + C_1) + (C_0 + C_1 + C_2) - (C_0 + C_1 + C_2 + C_3) + \ldots + (-1)^{n-1} (C_0 + C_1 + \ldots + C_{n-1}) \] ### Step 1: Simplifying the Expression Let's break down the expression term by term: 1. The first term is \(C_0\). 2. The second term is \(-(C_0 + C_1)\), which simplifies to \(-C_0 - C_1\). 3. The third term is \((C_0 + C_1 + C_2)\), which simplifies to \(C_0 + C_1 + C_2\). 4. The fourth term is \(-(C_0 + C_1 + C_2 + C_3)\), which simplifies to \(-C_0 - C_1 - C_2 - C_3\). Continuing this pattern, we can see that each pair of terms will contribute a negative value of the next odd indexed coefficient. ### Step 2: Grouping Terms Grouping the terms gives us: \[ C_0 - (C_0 + C_1) + (C_0 + C_1 + C_2) - (C_0 + C_1 + C_2 + C_3) + \ldots \] This can be rearranged to: \[ -C_1 - C_3 - C_5 - \ldots - C_{n-1} \] ### Step 3: Using Binomial Theorem Now, we can use the binomial theorem to evaluate the sums: 1. When \(x = 1\): \[ (1 + 1)^n = 2^n = C_0 + C_1 + C_2 + \ldots + C_n \] 2. When \(x = -1\): \[ (1 - 1)^n = 0 = C_0 - C_1 + C_2 - C_3 + \ldots + (-1)^n C_n \] ### Step 4: Setting Up the Equations Let’s denote the two equations we derived: - Equation 1: \[ C_0 + C_1 + C_2 + \ldots + C_n = 2^n \] - Equation 2: \[ C_0 - C_1 + C_2 - C_3 + \ldots + (-1)^n C_n = 0 \] ### Step 5: Subtracting the Equations Now, subtract Equation 2 from Equation 1: \[ (2^n) - 0 = (C_0 + C_1 + C_2 + \ldots + C_n) - (C_0 - C_1 + C_2 - C_3 + \ldots + (-1)^n C_n) \] This simplifies to: \[ 2^n = 2(C_1 + C_3 + C_5 + \ldots) \] ### Step 6: Solving for Odd Coefficients From this, we can find that: \[ C_1 + C_3 + C_5 + \ldots = \frac{2^n}{2} = 2^{n-1} \] ### Step 7: Final Expression Thus, the original expression evaluates to: \[ -C_1 - C_3 - C_5 - \ldots - C_{n-1} = -\left(2^{n-1}\right) = -2^{n-1} \] ### Conclusion The final answer is: \[ \boxed{-2^{n-1}} \]

To solve the given problem, we start with the binomial expansion of \((1+x)^n\): \[ (1+x)^n = C_0 + C_1 x + C_2 x^2 + \ldots + C_n x^n \] where \(C_r = \binom{n}{r}\). ...
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CENGAGE ENGLISH-BINOMIAL THEOREM-Multiple Correct Answer Type
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  3. The middle term in the expansion of (x/2+2)^8 is 1120, then x in R is...

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  4. In the expansion of (3-sqrt(17/4+3sqrt2))^15 the 11th term is a

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  5. For the expansion (x sin p + x^(-1)cos p)^(10), (p in R),

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  6. For which of the following values of x ,5t h term is the numerically g...

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  7. Which of the following is/are true ?

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  8. If sum(r=0)^(n) (r)/(""^(n)C(r))= sum(r=0)^(n) (n^(2)-3n+3)/(2.""^(n)C...

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  9. The value of .^(n)C(1)+.^(n+1)C(2)+.^(n+2)C(3)+"….."+.^(n+m-1)C(m) is ...

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  10. The number of terms in the expansion of (x^2+1+1/x^2)^n, n in N , is:

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  11. In the expansion of (7^(1//3)+11^(1//9))^(6561) , there are exactly 73...

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  12. If (1+x)^(n) = C(0) + C(1)x + C(2)x^(2) + "….." + C(n)x^(n), then C(0)...

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  13. In the expansion of (a+b)^(n), if two consecutive terms are equal, the...

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  14. If for z as real or complex, (1+z^2+z^4)^8=C0+C1z2+C2z4++C(16)z^(32)t ...

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  15. If f(m) = sum(i=0)^m ({:(30),(30-i):})({:(20),(m-i):}) where ({:(p),(...

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  16. If (1+x)^n=C0+C1x+C2x2++Cn x^n , n in N ,t h e nC0-C1+C2-+(-1)^(n-1)C...

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  17. If sum(r=0)^(n) (pr+2).""^(n)C(r)=(25)(64) where n, p in N, then (a) p...

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  18. If (x+1/x+1)^(6)=a(0)+(a(1)x+(b(1))/(x))+(a(2)x^(2)+(b(2))/(x^(2)))+"....

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  19. Find the value of .^(20)C(0) xx .^(13)C(10) - .^(20)C(1) xx .^(12)C(...

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  20. The sum 2 xx ""^(40)C(2) + 6 xx ""^(40)C(3) + 12 xx ""^(40)C(4) + 20 x...

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