alleryIf a = 2i + 3j + k and b = i − j + 2k, then a · b equals:
A$6$
B$1$
C$3$
D$5$
Answer & Solution
Correct answer: B. $1$
We have a · b = (2)(1) + (3)(-1) + (1)(2).
That is a · b = 2 − 3 + 2.
So a · b = 1.
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