Question

The magnitudes of vectors A, B and C are 3, 4 and 5 units
respectively. If A+B=C, the angle between A and B is​

Answer 1

Answer:

angle =90°

Explanation:

According to formula

${r}^{2} = {a}^{2} + {b}^{2} + 2ab \cos( \alpha ) \\ {5}^{2} = {3}^{2} + {4}^{2} + 2 \times 3 \times 4 \times \cos( \alpha ) \\ 25 = 25 + 24 \cos( \alpha ) \\ 24 \cos( \alpha ) = 0 \\ \cos( \alpha ) = 0 \\ \alpha = 90$