Question

The magnitude of two vectors are 12 and 18 units and their resultant is 24 units find the angle between the two vectors

Answer 1

$24 = \sqrt{ {12}^{2} + {8}^{2} + 2 \times 12 \times 18 \cos( \theta ) }$

$sbs$

$576 = {144 + 324 + 432 \cos( \theta ) }$

$576 - 468 = 432 \cos( \theta )$

$108 = 432 \cos( \theta )$

$\cos( \theta ) = \frac{1}{4}$

$\theta = { \cos }^{ - 1} (\frac{1}{4} )$