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If \vec{a}'=\hat{i}+\hat{j},\; \vec{b}'=\hat{i}-\hat{j}+2\hat{k}\; and \; \vec{c}'=2\hat{i}+\hat{j}-\hat{k}.   Then altitude of the parallelepiped formed by the vectors

 \vec{a},\; \vec{b},\; \vec{c} having base formed by  \vec{b},\;and\; \vec{c} is     \left ( \vec{a},\; \vec{b},\; \vec{c}\; and\; \vec{a}\; ',\vec{b}\: ',\vec{c}\; ',\right) are resciprocal systems of vectors 

 

 

Option: 1

1


Option: 2

\frac{3\sqrt{2}}{2}      


Option: 3

\frac{1}{\sqrt{6}}


Option: 4

\frac{1}{\sqrt{2}}


Answers (1)

best_answer

 

Scalar , Dot or Inner Product -

Scalar product of two vector \vec{A} & \vec{B} written as \vec{A} \cdot \vec{B} is a scalar quantity given by the product of magnitude of \vec{A} & \vec{B} and the cosine of smaller angle between them.

\vec{A}\cdot \vec{B}= A\, B\cdot \cos \Theta

- wherein

showing representation of scalar products of vectors.

 

 

Vector or cross product -

Vector or cross product of two vector \vec{A} & \vec{B} written asA\times B is a single vector whose magnitude is equal to product of magnitude of \vec{A} & \vec{B} and the sine of smaller angle\Theta  between them.

\vec A\times \vec B= A\, B\sin \Theta

- wherein

Figure 6 shows representation of vector or cross product of vectors.

 

shows representation of vector or cross product of vectors

 

 

Volume of the parallelopiped formed by  \vec{a},'\; \vec{b},'\; \vec{c},' is  4

Volume of the parallelopiped formed by  \vec{a},'\; \vec{b},'\; \vec{c},' is   \frac{1}{4}

           \vec{b}\times \vec{c}=\frac{\left ( \vec{c}'\times \vec{a}' \right )\times \vec{c}}{4}=\frac{1}{4}\vec{a}\; '

\therefore \; \; \left | \vec{b}\times \vec{c} \right |\frac{\sqrt{2}}{4}=\frac{1}{2\sqrt{2}}

\       length of altitude =  \frac{1}{4}\times 2\sqrt{2}=\frac{1}{\sqrt{2}}

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sudhir.kumar

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