A) \[30{}^\circ \]
B) \[45{}^\circ \]
C) \[60{}^\circ \]
D) \[90{}^\circ \]
Correct Answer: B
Solution :
Given, \[\vec{A}=-\hat{i}+2\hat{j}-3\hat{k}\] \[\hat{B}=4\hat{i}-2\hat{j}+6\hat{k}\] Let angle made by \[(\vec{A}+\vec{B})\]with \[x-\]axis is \[\theta .\] \[\cos \theta =\frac{(\vec{A}+\vec{B}).\hat{i}}{|\vec{A}+\vec{B}|.|\hat{i}|}=\frac{(3\hat{i}+3\hat{k}).\hat{i}}{\sqrt{9+9}.1}\] \[=\frac{3}{3\sqrt{2}}=\frac{1}{\sqrt{2}}\] \[\therefore \] \[\theta ={{45}^{o}}\]You need to login to perform this action.
You will be redirected in
3 sec