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If |(x^(n),x^(n+2),x^(n+3)),(y^(n),y^(n+...

If `|(x^(n),x^(n+2),x^(n+3)),(y^(n),y^(n+2),y^(n+3)),(z^(n),z^(n+2),z^(n+3))|`
`= (x -y) (y -z) (z -x) ((1)/(x) + (1)/(y) + (1)/(z))`, then n equals

A

1

B

`-1`

C

2

D

`-2`

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The correct Answer is:
To solve the given determinant equation, we need to find the value of \( n \) such that: \[ |(x^n, x^{n+2}, x^{n+3}), (y^n, y^{n+2}, y^{n+3}), (z^n, z^{n+2}, z^{n+3})| = (x - y)(y - z)(z - x) \left( \frac{1}{x} + \frac{1}{y} + \frac{1}{z} \right) \] **Step 1: Calculate the determinant.** The determinant can be expanded as follows: \[ D = \begin{vmatrix} x^n & x^{n+2} & x^{n+3} \\ y^n & y^{n+2} & y^{n+3} \\ z^n & z^{n+2} & z^{n+3} \end{vmatrix} \] Using properties of determinants, we can factor out common terms from each column: \[ D = \begin{vmatrix} x^n & x^{n+2} & x^{n+3} \\ y^n & y^{n+2} & y^{n+3} \\ z^n & z^{n+2} & z^{n+3} \end{vmatrix} = \begin{vmatrix} 1 & x^2 & x^3 \\ 1 & y^2 & y^3 \\ 1 & z^2 & z^3 \end{vmatrix} \cdot x^n y^n z^n \] **Step 2: Calculate the simplified determinant.** Now, we compute the determinant of the simplified matrix: \[ D' = \begin{vmatrix} 1 & x^2 & x^3 \\ 1 & y^2 & y^3 \\ 1 & z^2 & z^3 \end{vmatrix} \] Using the determinant formula for a \( 3 \times 3 \) matrix, we have: \[ D' = 1 \cdot (y^2 z^3 - y^3 z^2) - 1 \cdot (x^2 z^3 - x^3 z^2) + 1 \cdot (x^2 y^3 - x^3 y^2) \] This simplifies to: \[ D' = (y^2 z^3 - y^3 z^2) - (x^2 z^3 - x^3 z^2) + (x^2 y^3 - x^3 y^2) \] Factoring out common terms, we can express it as: \[ D' = (y - z)(z - x)(x - y) \] **Step 3: Combine results.** Thus, we can write: \[ D = (y - z)(z - x)(x - y) \cdot x^n y^n z^n \] **Step 4: Set the equation equal to the given expression.** Now we equate this to the right-hand side of the original equation: \[ (y - z)(z - x)(x - y) \cdot x^n y^n z^n = (x - y)(y - z)(z - x) \left( \frac{1}{x} + \frac{1}{y} + \frac{1}{z} \right) \] **Step 5: Simplify and solve for \( n \).** Notice that both sides have the factor \( (y - z)(z - x)(x - y) \). We can cancel this out (assuming \( x, y, z \) are distinct): \[ x^n y^n z^n = \left( \frac{1}{x} + \frac{1}{y} + \frac{1}{z} \right) \] The right-hand side can be rewritten as: \[ \frac{yz + zx + xy}{xyz} \] Thus, we have: \[ x^n y^n z^n = \frac{yz + zx + xy}{xyz} \] Multiplying both sides by \( xyz \): \[ x^{n+1} y^{n+1} z^{n+1} = yz + zx + xy \] **Step 6: Determine the value of \( n \).** To satisfy this equation for all \( x, y, z \), we can see that \( n + 1 \) must equal 0, leading to: \[ n + 1 = 0 \implies n = -1 \] Thus, the final answer is: \[ \boxed{-1} \]

To solve the given determinant equation, we need to find the value of \( n \) such that: \[ |(x^n, x^{n+2}, x^{n+3}), (y^n, y^{n+2}, y^{n+3}), (z^n, z^{n+2}, z^{n+3})| = (x - y)(y - z)(z - x) \left( \frac{1}{x} + \frac{1}{y} + \frac{1}{z} \right) \] **Step 1: Calculate the determinant.** ...
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OBJECTIVE RD SHARMA-DETERMINANTS-Section I - Solved Mcqs
  1. If w is a complex cube root of unity. |(a,b,c),(b,c,a),(c,a,b)| = -(...

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  2. If omegais an imaginary cube root of unity, then the value of the det...

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  3. If |(x^(n),x^(n+2),x^(n+3)),(y^(n),y^(n+2),y^(n+3)),(z^(n),z^(n+2),z^(...

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  4. If f(x) =|(1,x,(x+1)),(2x,x(x-1),(x+1)x),(3x(x-1), x(x-1)(x-2),x(x-1)(...

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  5. Given a(i)^(2) + b(i)^(2) + c(i)^(2) = 1, i = 1, 2, 3 and a(i) a(j) + ...

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  6. If alpha,beta and gamma are such that alpha+beta+gamma=0, then |(1,cos...

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  7. The value of the determinant |(cos alpha, -sin alpha,1),(sin alpha,cos...

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  8. If Delta = |(cos alpha,- sin alpha,1),(sin alpha,cos alpha,1),(cos (al...

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  9. Let D(r) = |(a,2^(r),2^(16) -1),(b,3(4^(r)),2(14^(16) -1)),(c,7(8^(r))...

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  10. If Delta = |(cos (alpha(1) - beta(1)),cos (alpha(1) - beta(2)),cos (al...

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  11. The determinant |(y^(2),-xy,x^(2)),(a,b,c),(a',b',c')| is equal to

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  12. If |[p,q-y,r-z],[p-x,q,r-z],[p-x,q-y,r]|=0 find the value of p/x+q/y+r...

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  13. The number of distinct real roots of |(sinx, cosx, cosx),(cos x,sin x,...

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  14. The value of a for which system of equation , a^3x+(a+1)^3y+(a+2)^3z=0...

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  15. Let A = [(1,sin theta,1),(- sin theta,1,sin theta),(-1,-sin theta,1)],...

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  16. Let |(x,2,x),(x^(2),x,6),(x,x,6)| = ax^(4) + bx^(3) + cx^(2) + dx + e ...

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  17. If Delta(1) = |(1,1,1),(a,b,c),(a^(2),b^(2),c^(2))|, Delta(2) = |(1,bc...

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  18. If Dk=|1nn2k n^2+n+2n^2+n2k-1n^2n^2+n+2|a n d sum(k=1)^n Dk=48 ,t h e...

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  19. Let |(1 +x,x,x^(2)),(x,1 +x,x^(2)),(x^(2),x,1 +x)| = ax^(5) + bx^(4) +...

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  20. If A = int(1)^(sintheta) (t)/(1 + r^(2)) dt and B = int(1)^("cosec"the...

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