Question

Apply Dot product of two vector, find angle between the vectors 1 + j + k and 3i - j + 2k​

Answer 1

Answer:

51.89

Step-by-step explanation:

$cos∅ = \frac{( i+j+k).(3i - j + 2k)}{ \sqrt{ {1}^{2} + {1}^{2} + {1}^{2} } \times \sqrt{ {3}^{2} + {( - 1)}^{2} + {2}^{2} } } \\ = \frac{3 - 1 + 2}{ \sqrt{3} \times \sqrt{14} } \\ = \frac{4}{ \sqrt{42} } \\ ∅ = { \cos}^{ - 1} ( \frac{4}{ \sqrt{41} } ) \\ = 51.89°$

Angle between i + j + k and 3i - j + 2k is 51.89° or 52°