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The scalar vecA.(vecB+vecC)xx(vecA+vecB+...

The scalar `vecA.(vecB+vecC)xx(vecA+vecB+vecC)` equals (A) 0 (B) `[vecA vecB vecC]+[vecB vecC vecA]` (C) `[vecA vecB vecC]` (D) none of these

A

0

B

`[vecA vecB vecC]+ [vecB vecC vecA] `

C

`[vecA vecB vecC]`

D

none of these

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The correct Answer is:
To solve the problem, we need to evaluate the expression \( \vec{A} \cdot (\vec{B} + \vec{C}) \times (\vec{A} + \vec{B} + \vec{C}) \). ### Step 1: Expand the expression We start by expanding the expression using the distributive property of the dot product and the cross product. \[ \vec{A} \cdot (\vec{B} + \vec{C}) \times (\vec{A} + \vec{B} + \vec{C}) = \vec{A} \cdot \left( \vec{B} \times (\vec{A} + \vec{B} + \vec{C}) + \vec{C} \times (\vec{A} + \vec{B} + \vec{C}) \right) \] ### Step 2: Apply the cross product Now we can apply the cross product to each term separately: \[ = \vec{A} \cdot \left( \vec{B} \times \vec{A} + \vec{B} \times \vec{B} + \vec{B} \times \vec{C} + \vec{C} \times \vec{A} + \vec{C} \times \vec{B} + \vec{C} \times \vec{C} \right) \] ### Step 3: Simplify using properties of cross product We know that the cross product of any vector with itself is zero, i.e., \( \vec{B} \times \vec{B} = 0 \) and \( \vec{C} \times \vec{C} = 0 \). Thus, we can simplify: \[ = \vec{A} \cdot \left( \vec{B} \times \vec{A} + \vec{B} \times \vec{C} + \vec{C} \times \vec{A} + \vec{C} \times \vec{B} \right) \] ### Step 4: Evaluate the dot products Now we can evaluate the dot products: 1. \( \vec{A} \cdot (\vec{B} \times \vec{A}) = 0 \) (since the dot product of a vector with the cross product of itself and another vector is zero). 2. \( \vec{A} \cdot (\vec{C} \times \vec{C}) = 0 \) (same reasoning). 3. \( \vec{A} \cdot (\vec{B} \times \vec{C}) \) remains as is. 4. \( \vec{A} \cdot (\vec{C} \times \vec{B}) \) also remains as is. Thus, we have: \[ = 0 + 0 + \vec{A} \cdot (\vec{B} \times \vec{C}) + \vec{A} \cdot (\vec{C} \times \vec{B}) \] ### Step 5: Use the scalar triple product property Using the property of scalar triple product, we know that \( \vec{A} \cdot (\vec{B} \times \vec{C}) = \vec{B} \cdot (\vec{C} \times \vec{A}) \). Therefore, we can simplify: \[ = 0 + 0 = 0 \] ### Conclusion Thus, the final answer is: \[ \vec{A} \cdot (\vec{B} + \vec{C}) \times (\vec{A} + \vec{B} + \vec{C}) = 0 \] ### Final Answer The correct option is (A) 0. ---

To solve the problem, we need to evaluate the expression \( \vec{A} \cdot (\vec{B} + \vec{C}) \times (\vec{A} + \vec{B} + \vec{C}) \). ### Step 1: Expand the expression We start by expanding the expression using the distributive property of the dot product and the cross product. \[ \vec{A} \cdot (\vec{B} + \vec{C}) \times (\vec{A} + \vec{B} + \vec{C}) = \vec{A} \cdot \left( \vec{B} \times (\vec{A} + \vec{B} + \vec{C}) + \vec{C} \times (\vec{A} + \vec{B} + \vec{C}) \right) \] ...
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CENGAGE ENGLISH-DIFFERENT PRODUCTS OF VECTORS AND THEIR GEOMETRICAL APPLICATIONS -single correct answer type
  1. The scalar vecA.(vecB+vecC)xx(vecA+vecB+vecC) equals (A) 0 (B) [vecA v...

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  2. For non-zero vectors veca, vecb and vecc , |(veca xx vecb) .vecc = |ve...

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  3. The volume of he parallelepiped whose sides are given by vec O A=2i...

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  4. Let veca,vecb,vecc be three noncolanar vectors and vecp,vecq,vecr are ...

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

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  6. If veca,vecb and vecc are non coplanar and unit vectors such that veca...

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  7. Let vecu,vecv and vecw be vectors such that vecu+ vecv + vecw =0 if |v...

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  8. If veca, vecb and vecc are three non-coplanar vectors, then (veca + ve...

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  9. Let vecp,vecq, vecr be three mutually perpendicular vectors of the sam...

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

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  11. Let veca = 2i + j+k, vecb = i+ 2j -k and a unit vector vecc be coplana...

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  12. If the vectors veca,vecb,vecc form the sides BC,CA and AB respectively...

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  13. Let the vectors veca, vecb,vecc and vecd be such that (vecaxxvecb)xx(v...

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  14. If veca,vecb, vecc are unit coplanar vectors then the scalar triple pr...

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  15. if hata, hatb and hatc are unit vectors. Then |hata - hatb|^(2) + |hat...

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  16. If veca and vecb are two unit vectors such that veca+2vecb and 5veca-4...

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  17. Let vecV = 2hati +hatj - hatk and vecW= hati + 3hatk . if vecU is a u...

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  18. Find the value of a so that the volume of the parallelopiped formed b...

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  19. If veca = (hati + hatj +hatk), veca. vecb= 1 and vecaxxvecb = hatj -ha...

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  20. The unit vector which is orthogonal to the vector 5hati + 2hatj + 6hat...

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