The vectors a and b are given in terms of two perpendicular units vectors i and j on a plane by a = 2i - 3j, b = -i + 2j. Find the magnitude of the vector a + 3b
A
2
B
4
C
\(\sqrt{10}\)
D
35
E
2.2
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
a = 2i - 3j - 3i + 6j
= -i + 3j
= \(\sqrt{5 \times 2}\)
= \(\sqrt{10}\)
Source: Myschool Past Questions Archive (Record #32726)