Question

A vector $3i+4j$ rotates about its tail through an angle $37^{\circ }$ in anti clockwise direction then the new vector is

• A. $-3i+4j$
• B. $3i-4j$
• C. 5 $j$
• D. 5 $i$

Answer 1

Answer: (C)

$A=\sqrt{A_x^2+A_y^2}$ and $\theta ={\tan }^{-1}\left(\frac{A_y}{A_x}\right)$