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If the vectors veca=hati+ahatj+a^(2)hatk...

If the vectors `veca=hati+ahatj+a^(2)hatk, vecb=hati+bhatj+b^(2)hatk, vecc=hati+chatj+c^(2)hatk` are three non-coplanar vectors and `|(a, a^(2), 1+a^(3)),(b,b^(2),1+b^(3)),(c,c^(2),1+c^(3))|=0` , then the value of `abc` is

A

0

B

1

C

2

D

`-1`

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To solve the problem, we need to find the value of \( abc \) given the condition that the determinant \[ \left| \begin{array}{ccc} a & a^2 & 1 + a^3 \\ b & b^2 & 1 + b^3 \\ c & c^2 & 1 + c^3 \end{array} \right| = 0 \] ### Step 1: Write the determinant We start with the determinant: \[ D = \left| \begin{array}{ccc} a & a^2 & 1 + a^3 \\ b & b^2 & 1 + b^3 \\ c & c^2 & 1 + c^3 \end{array} \right| \] ### Step 2: Split the determinant Using the property of determinants, we can express the third column as a sum of two columns: \[ D = \left| \begin{array}{ccc} a & a^2 & 1 \\ b & b^2 & 1 \\ c & c^2 & 1 \end{array} \right| + \left| \begin{array}{ccc} a & a^2 & a^3 \\ b & b^2 & b^3 \\ c & c^2 & c^3 \end{array} \right| \] Let \( D_1 = \left| \begin{array}{ccc} a & a^2 & 1 \\ b & b^2 & 1 \\ c & c^2 & 1 \end{array} \right| \) and \( D_2 = \left| \begin{array}{ccc} a & a^2 & a^3 \\ b & b^2 & b^3 \\ c & c^2 & c^3 \end{array} \right| \). Thus, we have: \[ D = D_1 + D_2 = 0 \] ### Step 3: Analyze \( D_1 \) The determinant \( D_1 \) can be simplified by noticing that the first two columns are polynomial expressions in \( a, b, c \): \[ D_1 = \left| \begin{array}{ccc} a & a^2 & 1 \\ b & b^2 & 1 \\ c & c^2 & 1 \end{array} \right| = \left| \begin{array}{ccc} 1 & a & a^2 \\ 1 & b & b^2 \\ 1 & c & c^2 \end{array} \right| \quad \text{(after interchanging columns)} \] This determinant represents the Vandermonde determinant, which is non-zero if \( a, b, c \) are distinct. ### Step 4: Analyze \( D_2 \) The determinant \( D_2 \) can be expressed as: \[ D_2 = \left| \begin{array}{ccc} a & a^2 & a^3 \\ b & b^2 & b^3 \\ c & c^2 & c^3 \end{array} \right| = \left| \begin{array}{ccc} 1 & a & a^2 \\ 1 & b & b^2 \\ 1 & c & c^2 \end{array} \right| \quad \text{(after interchanging columns)} \] This determinant is also a Vandermonde determinant and is non-zero if \( a, b, c \) are distinct. ### Step 5: Set up the equation Since \( D_1 + D_2 = 0 \) and both \( D_1 \) and \( D_2 \) are non-zero, we can conclude that: \[ D_1 = -D_2 \] ### Step 6: Non-coplanarity condition Given that the vectors are non-coplanar, the scalar triple product must be non-zero. Therefore, the condition \( 1 + abc = 0 \) must hold, leading to: \[ abc = -1 \] ### Conclusion Thus, the value of \( abc \) is: \[ \boxed{-1} \]
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VMC MODULES ENGLISH-VECTORS -LEVEL -1
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  2. The vector vec a has the components 2p and 1 w.r.t. a rectangular C...

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  3. If the vectors veca=hati+ahatj+a^(2)hatk, vecb=hati+bhatj+b^(2)hatk, v...

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  4. If veca =hati + hatj, vecb = hati - hatj + hatk and vecc is a unit vec...

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  5. If the vectors veca and vecb are mutually perpendicular, then veca xx ...

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  6. If veca is perpendicular to vecb and vecr is a non-zero vector such th...

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  7. Let veca=hati-hatj, vecb=hatj-hatk, vecc=hatk-hati. If hatd is a unit ...

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  8. Given that veca,vecc,vecd are coplanar the value of (veca + vecd).{vec...

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  9. let veca , vecb and vecc be three vectors having magnitudes 1, 1 and 2...

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  10. If A(1,-1,-3),B(2,1,-2) and C(-5,2,-6) are the position vectors of the...

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  11. If |{:(veca,vecb,vecc),(veca.veca,veca.vecb,veca.vecc),(veca.vecc,vecb...

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  12. Let vec(A)D be the angle bisector of angle A" of " Delta ABC such th...

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  13. Let veca = 2hati + hatj + hatk, and vecb = hati+ hatj if c is a vecto...

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  14. If veca and vecb are two unit vectors and theta is the angle between t...

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  15. If veca + 2 vecb + 3 vecc = vec0 " then " veca xx vecb + vecb xx vecc...

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  16. If veca,vecb,vecc and vecp,vecq,vecr are reciprocal system of vectors,...

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  17. For any four vectors veca, vecb, vecc, vecd the expressions (vecb xx v...

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  18. If veca xx (vec b xx vecc) is perpendicular to (veca xx vecb ) xx vecc...

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  19. The three vectors hat i+hat j,hat j+hat k, hat k+hat i taken two at a ...

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  20. Let p and q be the position vectors of P and Q respectively with respe...

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