Question

Resultant of two unit vector u1 and u2 result of two unit vector is also a unit vector find angle biletween the two vector​

Answer 1

Answer:

120°

Explanation:

Answer 2

Answer:

Let angle be alpha resultant

$r = \sqrt{ {1}^{2} + {1}^{2} + 2(1)(1) \cos( \alpha ) } = 1 \\ \sqrt{2(1 + \cos( \alpha )) } = 1 \\ \sqrt{4 \cos {}^{2} ( \frac{ \alpha }{2} ) } = 1 \\ \cos( \frac{ \alpha }{2} ) = \pm \: \frac{1}{2} \\ \frac{ \alpha }{2} = \frac{\pi}{3} \: \: and \: \: \frac{2\pi}{3} \\ \\ \alpha = \frac{2\pi}{3 } \: \: and \: \: \frac{4\pi}{3}$