Home
Class 12
PHYSICS
the value of (vecA+vecB)xx(vecA-vecB) is...

the value of `(vecA+vecB)xx(vecA-vecB)` is

A

0

B

`A^2-B^2`

C

`vecBxxvecA`

D

`2(vecBxxvecA)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem of finding the value of \((\vec{A} + \vec{B}) \times (\vec{A} - \vec{B})\), we can use the distributive property of the cross product. Here’s a step-by-step breakdown of the solution: ### Step 1: Write the expression We start with the expression we need to evaluate: \[ (\vec{A} + \vec{B}) \times (\vec{A} - \vec{B}) \] ### Step 2: Apply the distributive property Using the distributive property of the cross product, we can expand the expression: \[ \vec{A} \times \vec{A} + \vec{A} \times (-\vec{B}) + \vec{B} \times \vec{A} + \vec{B} \times (-\vec{B}) \] This simplifies to: \[ \vec{A} \times \vec{A} - \vec{A} \times \vec{B} + \vec{B} \times \vec{A} - \vec{B} \times \vec{B} \] ### Step 3: Simplify the terms Now, we know that the cross product of any vector with itself is zero: \[ \vec{A} \times \vec{A} = \vec{0} \quad \text{and} \quad \vec{B} \times \vec{B} = \vec{0} \] Thus, the expression reduces to: \[ \vec{0} - \vec{A} \times \vec{B} + \vec{B} \times \vec{A} + \vec{0} \] This simplifies further to: \[ -\vec{A} \times \vec{B} + \vec{B} \times \vec{A} \] ### Step 4: Use the anti-commutative property The cross product is anti-commutative, meaning: \[ \vec{B} \times \vec{A} = -(\vec{A} \times \vec{B}) \] Substituting this into our expression gives: \[ -\vec{A} \times \vec{B} - \vec{A} \times \vec{B} = -2(\vec{A} \times \vec{B}) \] ### Final Result Thus, the final value of \((\vec{A} + \vec{B}) \times (\vec{A} - \vec{B})\) is: \[ -2(\vec{A} \times \vec{B}) \]

To solve the problem of finding the value of \((\vec{A} + \vec{B}) \times (\vec{A} - \vec{B})\), we can use the distributive property of the cross product. Here’s a step-by-step breakdown of the solution: ### Step 1: Write the expression We start with the expression we need to evaluate: \[ (\vec{A} + \vec{B}) \times (\vec{A} - \vec{B}) \] ...
Promotional Banner

Similar Questions

Explore conceptually related problems

For vectors vecA=3hati-4hatj+5hatk and vecB=hati-hatj-hatk , calculate the value of (vecA+vecB)xx(vecA-vecB)

(a) Show that vector adition is commutative but vector subtraction is non-commutative . (b) For vectors vecA=3hati-4hatj+5hatk and vecB=hati-hatj-hatk , calculate the value of (vecA+vecB)xx(vecA-vecB)

What is the value of (vecA + vecB) * ( vecA xx vecB) ?

Find the value of (veca+vecb)xx[vecaxx((veca-vecb)xxvecb)]

If veca=hati+hatj+hatk , vecb=2hati+hatj-hatk and vecc=4hati+3hatj+hatk then value of ((veca+vecb)xx(veca -(veca-vecb)xxvecb)))xxvecc is

Let veca, vecb and vecc are three unit vectors in a plane such that they are equally inclined to each other, then the value of (veca xx vecb).(vecb xx vecc) + (vecb xx vecc). (vecc xx veca)+(vecc xx veca). (veca xx vecb) can be

vecA and vecB are two vectors. (vecA + vecB) xx (vecA - vecB) can be expressed as :

The value of veca.(vecb+vecc)xx(veca+vecb+vecc) , is

If veca=(3hati-hatj)/(sqrt(10)) and vecb=(hati+3hatj+hatk)/(sqrt(11)), then the value of (2veca+vecb)".[(veca xx vecb)xx(veca-3vecb)]

If veca and vecb are vectors in space given by veca=(hati-2hatj)/(sqrt(5)) vecb=(2hati+hatj+3hatk)/(sqrt(14)) then the value of (2veca+vecb).[(vecaxxvecb)xx(veca-2vecb)] , is