Find the magnitude and direction angle of the vector a given below. Express your answer to one decimal place.


$a = 12i - 18j$

• A. 21.6 and −56.3°
• B. 31.6 and 56.3°
• C. 21.6 and 56.3°
• D. 31.6 and −56.3°

Answer: (A)