If x, y and z are non-zero real numbers and v | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) Given,$\vec{a}=x \hat{i}+2 \hat{j}, \vec{b}=y \hat{j}+3 \hat{k}$ and $\vec{c}=x \hat{i}+y \hat{j}+z \hat{k}$.The cross product $\vec{a} 	imes \ve

Vedclass · Accepted Answer

$9$

Vedclass · Answer

(C) Given,$\vec{a}=x \hat{i}+2 \hat{j}, \vec{b}=y \hat{j}+3 \hat{k}$ and $\vec{c}=x \hat{i}+y \hat{j}+z \hat{k}$.The cross product $\vec{a} 	imes \vec{b}$ is given by:$\vec{a} 	imes \vec{b} = \begin{vmatrix} \hat{i} & \hat{j} & \hat{k} \ x & 2 & 0 \ 0 & y & 3 \end{vmatrix} = \hat{i}(6-0) - \hat{j}(3x-0) + \hat{k}(xy-0) = 6\hat{i} - 3x\hat{j} + xy\hat{k}$.Comparing this with the given $\vec{a} 	imes \vec{b} = z\hat{i} - 3\hat{j} + \hat{k}$,we get:$6 = z$,$-3x = -3 \Rightarrow x = 1$,and $xy = 1$.Since $x=1$,we have $1 \cdot y = 1 \Rightarrow y = 1$.Thus,$\vec{a} = \hat{i} + 2\hat{j}$,$\vec{b} = \hat{j} + 3\hat{k}$,and $\vec{c} = \hat{i} + \hat{j} + 6\hat{k}$.The scalar triple product $[\vec{a} \vec{b} \vec{c}]$ is the determinant of the components of $\vec{a}, \vec{b}, \vec{c}$:$[\vec{a} \vec{b} \vec{c}] = \begin{vmatrix} 1 & 2 & 0 \ 0 & 1 & 3 \ 1 & 1 & 6 \end{vmatrix} = 1(6-3) - 2(0-3) + 0(0-1) = 3 + 6 = 9$.

If $x, y$ and $z$ are non-zero real numbers and $\vec{a}=x \hat{i}+2 \hat{j}, \vec{b}=y \hat{j}+3 \hat{k}$ and $\vec{c}=x \hat{i}+y \hat{j}+z \hat{k}$ are such that $\vec{a} \times \vec{b}=z \hat{i}-3 \hat{j}+\hat{k}$,then $[\vec{a} \vec{b} \vec{c}]$ equals to

Similar Questions

$a, b, c$ are three non-zero,non-coplanar vectors and $p, q, r$ are three other vectors such that $p = \frac{b \times c}{a \cdot (b \times c)}$,$q = \frac{c \times a}{a \cdot (b \times c)}$,$r = \frac{a \times b}{a \cdot (b \times c)}$. Then $[p, q, r]$ equals

If $\bar{u}=\hat{\imath}-2 \hat{\jmath}+\hat{k}, \bar{v}=3 \hat{\imath}+\hat{k}$ and $\bar{w}=\hat{\jmath}-\hat{k}$,then the volume of the parallelepiped with $\bar{u} \times \bar{v}, \bar{u}+\bar{w}$ and $\bar{v}+\bar{w}$ as coterminus edges is

If $\vec{a}, \vec{b}, \vec{c}$ are three non-coplanar vectors and $\vec{r}$ is any vector,then $[\vec{b} \, \vec{c} \, \vec{r}] \vec{a} + [\vec{c} \, \vec{a} \, \vec{r}] \vec{b} + [\vec{a} \, \vec{b} \, \vec{r}] \vec{c} = \dots$

If $2 \hat{i}-\hat{j}+3 \hat{k}$,$-12 \hat{i}-\hat{j}-3 \hat{k}$,$-\hat{i}+2 \hat{j}-4 \hat{k}$ and $\lambda \hat{i}+2 \hat{j}-\hat{k}$ are the position vectors of four coplanar points,then $\lambda=$

If the points $A(2,1,-1), B(0,-1,0), C(4,0,4)$ and $D(2,0,x)$ are coplanar,then $x=$

Vedclass Test Series

Exam Paper Generator

Online Exam Module