Home
Class 12
MATHS
Statement 1: If veca, vecb are non zero ...

Statement 1: If `veca, vecb` are non zero and non collinear vectors, then
`vecaxxvecb=[(veca, vecb, hati)]hati+[(veca, vecb, hatj)]hatj+[(veca, vecb, hatk)]hatk`
Statement 2: For any vector `vecr`
`vecr=(vecr.hati)hati+(vecr.hatj)hatj+(vecr.hatk)hatk`

A

1

B

2

C

3

D

4

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given problem, we need to analyze the two statements provided and determine their validity step by step. ### Step 1: Analyze Statement 1 Statement 1 states: If \(\vec{a}\) and \(\vec{b}\) are non-zero and non-collinear vectors, then: \[ \vec{a} \times \vec{b} = [(\vec{a}, \vec{b}, \hat{i})] \hat{i} + [(\vec{a}, \vec{b}, \hat{j})] \hat{j} + [(\vec{a}, \vec{b}, \hat{k})] \hat{k} \] **Explanation:** - The left-hand side, \(\vec{a} \times \vec{b}\), represents the cross product of vectors \(\vec{a}\) and \(\vec{b}\). - The right-hand side consists of scalar triple products, which can be expressed as: - \((\vec{a}, \vec{b}, \hat{i})\) is the scalar triple product of \(\vec{a}\), \(\vec{b}\), and the unit vector in the x-direction \(\hat{i}\). - Similarly, \((\vec{a}, \vec{b}, \hat{j})\) and \((\vec{a}, \vec{b}, \hat{k})\) represent the scalar triple products with \(\hat{j}\) and \(\hat{k}\) respectively. **Verification:** - We can express the cross product \(\vec{a} \times \vec{b}\) in terms of its components: \[ \vec{a} \times \vec{b} = \begin{vmatrix} \hat{i} & \hat{j} & \hat{k} \\ a_1 & a_2 & a_3 \\ b_1 & b_2 & b_3 \end{vmatrix} \] - This determinant can be expanded to yield components in the \(\hat{i}\), \(\hat{j}\), and \(\hat{k}\) directions. - Thus, the expression on the right-hand side can be shown to equal \(\vec{a} \times \vec{b}\). **Conclusion:** - Statement 1 is **True**. ### Step 2: Analyze Statement 2 Statement 2 states: For any vector \(\vec{r}\): \[ \vec{r} = (\vec{r} \cdot \hat{i}) \hat{i} + (\vec{r} \cdot \hat{j}) \hat{j} + (\vec{r} \cdot \hat{k}) \hat{k} \] **Explanation:** - This statement represents the decomposition of a vector \(\vec{r}\) into its components along the coordinate axes. - The dot product \(\vec{r} \cdot \hat{i}\) gives the component of \(\vec{r}\) in the direction of \(\hat{i}\), and similarly for \(\hat{j}\) and \(\hat{k}\). **Verification:** - The vector \(\vec{r}\) can be expressed in terms of its components as: \[ \vec{r} = r_1 \hat{i} + r_2 \hat{j} + r_3 \hat{k} \] - Where \(r_1 = \vec{r} \cdot \hat{i}\), \(r_2 = \vec{r} \cdot \hat{j}\), and \(r_3 = \vec{r} \cdot \hat{k}\). - Therefore, the equation holds true. **Conclusion:** - Statement 2 is **True**. ### Final Conclusion: Both statements are true, and Statement 2 serves as a correct explanation for Statement 1. ### Final Answer: Both statements are true, and Statement 2 is a correct explanation for Statement 1. ---

To solve the given problem, we need to analyze the two statements provided and determine their validity step by step. ### Step 1: Analyze Statement 1 Statement 1 states: If \(\vec{a}\) and \(\vec{b}\) are non-zero and non-collinear vectors, then: \[ \vec{a} \times \vec{b} = [(\vec{a}, \vec{b}, \hat{i})] \hat{i} + [(\vec{a}, \vec{b}, \hat{j})] \hat{j} + [(\vec{a}, \vec{b}, \hat{k})] \hat{k} \] ...
Promotional Banner

Topper's Solved these Questions

  • SCALAR AND VECTOR PRODUCTS OF THREE VECTORS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Exercise|63 Videos
  • SCALAR AND VECTOR PRODUCTS OF THREE VECTORS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section I - Solved Mcqs|64 Videos
  • REAL FUNCTIONS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Chapter Test|58 Videos
  • SCALER AND VECTOR PRODUCTS OF TWO VECTORS

    OBJECTIVE RD SHARMA ENGLISH|Exercise Section I - Solved Mcqs|12 Videos

Similar Questions

Explore conceptually related problems

If veca vecb are non zero and non collinear vectors, then [(veca, vecb, veci)]hati+[(veca, vecb, vecj)]hatj+[(veca, vecb, veck)]hatk is equal to

If veca,vecb are non-collinear vectors, then [(veca,vecb,hati)]hati+[(veca,vecb,hatj)]hatj+[(veca,vecb,hatk)]hatk=

Consider three vectors veca , vecb and vecc Statement 1: vecaxxvecb = ((hatixxveca).vecb)hati+ ((hatj xx veca).vecb)hatj + (hatk xxveca).vecb)hatk Statement 2: vecc= (hati.vecc)hati+ (hatj .vecc) hatj + (hatk. vecc)hatk

If veca is any non-zero vector, then (veca.hati)hati+(veca.hatj)hatj+(veca.veck)hatk is equal to …….

If veca=hati+hatj, vecb=hatj+hatk, vec c hatk+hati , a unit vector parallel to veca+vecb+vecc .

Statement 1: Let vecr be any vector in space. Then, vecr=(vecr.hati)hati+(vecr.hatj)hatj+(vecr.hatk)hatk Statement 2: If veca, vecb, vecc are three non-coplanar vectors and vecr is any vector in space then vecr={([(vecr, vecb, vecc)])/([(veca, vecb, vecc)])}veca+{([(vecr, vecc, veca)])/([(veca, vecb, vecc)])}vecb+{([(vecr, veca, vecb)])/([(veca, vecb, vecc)])}vecc

If veca=2hati + hatj + hatk , vecb=hati + 2hatj + 2hatk then [veca vecb veci] hati + [veca vecb vecj] hatj + [veca vecb hatk] k is equal to

Find vecaxxvecb and |vecaxxvecb| if veca=2hati+hatj+3hatk and vecb=3hati+5hatj-2hatk

Find the projection of vecb+vecc on veca where veca=hati+2hatj+hatk, vecb=hati+3hatj+hatk and vecc=hati+hatk .

Find vecaxxvecb if veca=i+hatk and vecb=hati+hatj+hatk .