Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa

Let \overrightarrow{a}= 2\hat{i}-2\hat{j}-\hat{k} and \overrightarrow{b}= 6\hat{i}-3\hat{j}+2\hat{k} then angle \Theta between them equals:

Option: 1

\cos^{-1}\frac{16}{21}


Option: 2

\cos^{-1}\frac{19}{21}


Option: 3

\cos^{-1}\frac{17}{21}


Option: 4

\cos^{-1}\frac{13}{21}


Answers (1)

best_answer

\vec{a} \cdot \vec{b}=\left |\vec{a} \right |\left | \vec{b} \right | cos\Theta

\cos \Theta =\frac{\vec{a}.\vec{b}}{\left | \vec{a} \right |\left | \vec{b} \right |}

=\frac{12+6-2}{3*7}=\frac{16}{21}

\Theta = cos^{-1} \left ( \frac{16}{21} \right )

Posted by

Shailly goel

View full answer

Similar Questions