a
(a)Resultant of vectors \(\overrightarrow A \) and \(\overrightarrow B \)\(\overrightarrow R = \overrightarrow A + \overrightarrow B = 4\hat i + 3\hat j + 6\hat k - \hat i + 3\hat j - 8\hat k\)\(\overrightarrow R = 3\hat i + 6\hat j - 2\hat k\)\(\hat R = \frac{{\overrightarrow R }}{{|\vec R|}} = \frac{{3\hat i + 6\hat j - 2\hat k}}{{\sqrt {{3^2} + {6^2} + {{( - 2)}^2}} }} = \frac{{3\hat i + 6\hat j - 2\hat k}}{7}\)