Question

The angle made by the vector $A = \widehat{i} + \widehat{j}$ with x- axis is-

• A. (a) $90^{0}$
• A. (b) $45^{0}$
• A. (c) $22.5^{0}$
• A. (d) $30^{0}$

Answer 1

(b)

$\overrightarrow{A} = \widehat{i} + \widehat{j}$

$\cos\alpha = \frac{A_{x}}{|A|} = \frac{1}{\sqrt{2}} = \cos 45{^\circ}$

∴ $\alpha = 45^{0}$