The given vector is a → =5 i ^ − j ^ +2 k ^ .
The magnitude of vector a → is,
| a → |= 5 2 + ( −1 ) 2 + 2 2 = 30
Unit vector in direction of a → is,
a ^ = a → | a → | = 5 i ^ − j ^ +2 k ^ 30 = 5 30 i ^ − 1 30 j ^ + 2 30 k ^
Vector equation in the direction of a → with magnitude 8 is,
8 a ^ =8( 5 30 i ^ − 1 30 j ^ + 2 30 k ^ ) = 40 30 i ^ − 8 30 j ^ + 16 30 k ^
Thus, vector in the direction of a → with magnitude 8 is 40 30 i ^ − 8 30 j ^ + 16 30 k ^ .