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If veca=2hati + hatj+ hatk, vecb= hati+ ...

If `veca=2hati + hatj+ hatk, vecb= hati+ 2hatj + 2hatk,vecc = hati+ hatj + 2hatk and (1 + alpha) hati+ beta(1+ alpha)hatj+gamma(1+alpha)(1 + beta) hatk= vecaxx(vecb xx vecc) , " then " alpha, beta and gamma " are "`

A

`-2,-4,-2/3`

B

`2,-4,2/3`

C

`-2,4,2/3`

D

`2,4,-2/3`

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To solve the given problem step by step, we will follow the vector algebra rules and properties. ### Step 1: Define the vectors We are given the vectors: - \(\vec{a} = 2\hat{i} + \hat{j} + \hat{k}\) - \(\vec{b} = \hat{i} + 2\hat{j} + 2\hat{k}\) - \(\vec{c} = \hat{i} + \hat{j} + 2\hat{k}\) ### Step 2: Compute \(\vec{b} \times \vec{c}\) We will first find the cross product \(\vec{b} \times \vec{c}\). \[ \vec{b} \times \vec{c} = \begin{vmatrix} \hat{i} & \hat{j} & \hat{k} \\ 1 & 2 & 2 \\ 1 & 1 & 2 \end{vmatrix} \] Calculating the determinant: \[ = \hat{i} \begin{vmatrix} 2 & 2 \\ 1 & 2 \end{vmatrix} - \hat{j} \begin{vmatrix} 1 & 2 \\ 1 & 2 \end{vmatrix} + \hat{k} \begin{vmatrix} 1 & 2 \\ 1 & 1 \end{vmatrix} \] Calculating the individual determinants: \[ = \hat{i} (2 \cdot 2 - 2 \cdot 1) - \hat{j} (1 \cdot 2 - 2 \cdot 1) + \hat{k} (1 \cdot 1 - 2 \cdot 1) \] \[ = \hat{i} (4 - 2) - \hat{j} (2 - 2) + \hat{k} (1 - 2) \] \[ = 2\hat{i} + 0\hat{j} - \hat{k} = 2\hat{i} - \hat{k} \] ### Step 3: Compute \(\vec{a} \times (\vec{b} \times \vec{c})\) Now we need to compute \(\vec{a} \times (\vec{b} \times \vec{c})\): \[ \vec{a} \times (2\hat{i} - \hat{k}) = \begin{vmatrix} \hat{i} & \hat{j} & \hat{k} \\ 2 & 1 & 1 \\ 2 & 0 & -1 \end{vmatrix} \] Calculating the determinant: \[ = \hat{i} \begin{vmatrix} 1 & 1 \\ 0 & -1 \end{vmatrix} - \hat{j} \begin{vmatrix} 2 & 1 \\ 2 & -1 \end{vmatrix} + \hat{k} \begin{vmatrix} 2 & 1 \\ 2 & 0 \end{vmatrix} \] Calculating the individual determinants: \[ = \hat{i} (1 \cdot -1 - 1 \cdot 0) - \hat{j} (2 \cdot -1 - 1 \cdot 2) + \hat{k} (2 \cdot 0 - 1 \cdot 2) \] \[ = -\hat{i} - \hat{j} (-2 - 2) - 2\hat{k} \] \[ = -\hat{i} + 4\hat{j} - 2\hat{k} \] ### Step 4: Set the equation We are given that: \[ (1 + \alpha)\hat{i} + \beta(1 + \alpha)\hat{j} + \gamma(1 + \alpha)(1 + \beta)\hat{k} = -\hat{i} + 4\hat{j} - 2\hat{k} \] ### Step 5: Compare coefficients Now, we can compare the coefficients of \(\hat{i}\), \(\hat{j}\), and \(\hat{k}\): 1. For \(\hat{i}\): \[ 1 + \alpha = -1 \implies \alpha = -2 \] 2. For \(\hat{j}\): \[ \beta(1 + \alpha) = 4 \implies \beta(-1) = 4 \implies \beta = -4 \] 3. For \(\hat{k}\): \[ \gamma(1 + \alpha)(1 + \beta) = -2 \] Substituting \(\alpha = -2\) and \(\beta = -4\): \[ \gamma(-1)(-3) = -2 \implies 3\gamma = -2 \implies \gamma = -\frac{2}{3} \] ### Final Values Thus, the values of \(\alpha\), \(\beta\), and \(\gamma\) are: - \(\alpha = -2\) - \(\beta = -4\) - \(\gamma = -\frac{2}{3}\)

To solve the given problem step by step, we will follow the vector algebra rules and properties. ### Step 1: Define the vectors We are given the vectors: - \(\vec{a} = 2\hat{i} + \hat{j} + \hat{k}\) - \(\vec{b} = \hat{i} + 2\hat{j} + 2\hat{k}\) - \(\vec{c} = \hat{i} + \hat{j} + 2\hat{k}\) ...
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CENGAGE ENGLISH-DIFFERENT PRODUCTS OF VECTORS AND THEIR GEOMETRICAL APPLICATIONS -Exercises MCQ
  1. The condition for equations vecrxxveca = vecb and vecr xx vecc = vecd ...

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  2. If veca=2hati + hatj + hatk, vecb=hati + 2hatj + 2hatk then [veca vecb...

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  3. If veca=2hati + hatj+ hatk, vecb= hati+ 2hatj + 2hatk,vecc = hati+ hat...

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  4. Let (veca (x) = (sin x) hati+ (cos x) hatj and vecb(x) = (cos 2x) hati...

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  5. For any vectors veca and vecb, (veca xx hati) + (vecb xx hati) + ( vec...

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  6. If veca,vecb and vecc are three non coplanar vectors and vecr is any v...

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  7. If vecp = (vecbxxvecc)/([vecavecbvecc]), vecq=(veccxxveca)/([veca vecb...

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  8. A( vec a),B( vec b)a n dC( vec c) are the vertices of triangle A B ...

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  9. If veca , vecb and vecc are non- coplanar vectors and veca xx vecc is ...

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  10. If V be the volume of a tetrahedron and V ' be the volume of another...

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  11. [(veca xxvecb)xx(vecb xx vecc) (vecb xxvecc) xx (vecc xxveca)...

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  12. If vecr=x(1)(vecaxx vecb) + x(2) (vecb xxveca) + x(3)(vecc xxvecd) and...

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  13. If the vectors veca and vecb are perpendicular to each other then a ve...

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  14. If veca' = hati + hatj, vecb'= hati - hatj + 2hatk and vecc' = 2hati -...

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  15. If veca= hati +hatj, vecb= hatj + hatk, vecc = hatk + hati then in th...

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  16. If the unit vectors veca and vecb are inclined of an angle 2 theta ...

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  17. vecb and vecc are non- collinear if veca xx (vecb xx vecc) + (veca .ve...

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  18. Let veca.vecb=0 where veca and vecb are unit vectors and the vector ve...

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  19. veca and vecb are two given vectors. On these vectors as adjacent side...

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

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