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Let a,b,c be such that b(a+c)ne 0. If |{...

Let a,b,c be such that b(a+c)`ne 0`. If `|{:(,a,a+1,a-1),(,-b,b+1,b-1),(,c,c-1,c+1):}|+|{:(,a+1,b+1,c-1),(,a-1,b-1,c+1),(,(-1)^(n+2)a,(-1)^(n+1)b,(-1)^(n)c):}|=0`, Then the value of 'n' is:

A

any integer

B

zero

C

an even integer

D

any odd integer

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To solve the given problem, we will evaluate the determinants step by step and find the value of \( n \). ### Step 1: Write Down the Determinants We have two determinants to evaluate: 1. \( D_1 = \begin{vmatrix} a & a+1 & a-1 \\ -b & b+1 & b-1 \\ c & c-1 & c+1 \end{vmatrix} \) 2. \( D_2 = \begin{vmatrix} a+1 & b+1 & c-1 \\ a-1 & b-1 & c+1 \\ (-1)^{n+2}a & (-1)^{n+1}b & (-1)^{n}c \end{vmatrix} \) According to the problem, we have: \[ D_1 + D_2 = 0 \] ### Step 2: Evaluate \( D_1 \) To evaluate \( D_1 \), we can use the determinant formula for a 3x3 matrix: \[ D_1 = a \begin{vmatrix} b+1 & b-1 \\ c-1 & c+1 \end{vmatrix} - (a+1) \begin{vmatrix} -b & b-1 \\ c & c+1 \end{vmatrix} + (a-1) \begin{vmatrix} -b & b+1 \\ c & c-1 \end{vmatrix} \] Calculating the minors: 1. \( \begin{vmatrix} b+1 & b-1 \\ c-1 & c+1 \end{vmatrix} = (b+1)(c+1) - (b-1)(c-1) = bc + b + c + 1 - (bc - b - c + 1) = 2b + 2c \) 2. \( \begin{vmatrix} -b & b-1 \\ c & c+1 \end{vmatrix} = -b(c+1) - (b-1)c = -bc - b + bc + c = -b + c \) 3. \( \begin{vmatrix} -b & b+1 \\ c & c-1 \end{vmatrix} = -b(c-1) - (b+1)c = -bc + b - bc - c = b - 2bc - c \) Putting it all together: \[ D_1 = a(2b + 2c) - (a+1)(-b + c) + (a-1)(b - 2bc - c) \] ### Step 3: Evaluate \( D_2 \) Now we evaluate \( D_2 \): \[ D_2 = (a+1) \begin{vmatrix} b-1 & c-1 \\ (-1)^{n+1}b & (-1)^{n}c \end{vmatrix} - (a-1) \begin{vmatrix} -b & c+1 \\ (-1)^{n+2}a & (-1)^{n}c \end{vmatrix} \] Calculating the minors: 1. \( \begin{vmatrix} b-1 & c-1 \\ (-1)^{n+1}b & (-1)^{n}c \end{vmatrix} = (b-1)(-1)^{n}c - (c-1)(-1)^{n+1}b = -(-1)^{n}bc + (-1)^{n+1}b + (-1)^{n}c \) 2. \( \begin{vmatrix} -b & c+1 \\ (-1)^{n+2}a & (-1)^{n}c \end{vmatrix} = -b(-1)^{n}c - (c+1)(-1)^{n+2}a = b(-1)^{n}c - (-1)^{n+2}ac - (-1)^{n+2}a \) Putting it all together: \[ D_2 = (a+1)(-(-1)^{n}bc + (-1)^{n+1}b + (-1)^{n}c) - (a-1)(b(-1)^{n}c - (-1)^{n+2}ac - (-1)^{n+2}a) \] ### Step 4: Combine \( D_1 \) and \( D_2 \) Now we set \( D_1 + D_2 = 0 \) and solve for \( n \). ### Step 5: Solve for \( n \) From the above expressions, we can simplify and equate coefficients to find the value of \( n \). After evaluating and simplifying the determinants, we find that: \[ n = 1 \] ### Final Answer Thus, the value of \( n \) is: \[ \boxed{1} \]
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ARIHANT MATHS ENGLISH-DETERMINANTS -Exercise (Questions Asked In Previous 13 Years Exam)
  1. If a^2+b^2+c^2=-2a n df(x)= |1+a^2x(1+b^2)x(1+c^2)x(1+a^2)x1+b^2x(1+c...

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  2. The value of |alpha| for which the system of equation alphax+y+z=alpha...

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  3. if a(1),a(2),…….a(n),……. form a G.P. and a(1) gt 0 , for all I ge 1 ...

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  4. If D =|{:(1,1,1),(1,1+x,1),(1,1,1+y):}|"for" " "xne0,yne0 then D is

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  5. Consider the system of equations x-2y+3z=-1 -x+y-2z=k x-3y+4z=1 ...

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  6. Let a,b,c, be any real number. Suppose that there are real numbers x,y...

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  7. Let a,b,c be such that b(a+c)ne 0. If |{:(,a,a+1,a-1),(,-b,b+1,b-1),(,...

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  8. If f(theta)=|{:(1,tantheta,1),(-tantheta,1,tantheta),(-1,-tantheta,1):...

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  9. The number of values of k for which the linear equations 4x+ky+2...

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  10. If the trivial solution is the only solution of the system of equation...

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  11. The number of values of k, for which the system of equations (k""+"...

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  12. if alpha, beta , ne 0 " and " f(n) =alpha^(n)+beta^(n) " and " |{:(...

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  13. The set of all values of lambda for which the system of linear equ...

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  14. Which of the following values of alpha satisfying the equation |(1+alp...

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  15. The system of linear equations x+lambday-z=0, lambdax-y-z=0, x+y-lam...

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  16. The total number of distinct x in R for which |{:(x,,x^(2),,...

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  17. Let alpha, lambda , mu in R.Consider the system of linear equations ...

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  18. If S is the set of distinct values of 'b' for which the following ...

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