Question

d) Ift & j are two mutually perpendicular unit vectors, what is the value of
(2î +3j). (4î+5j)​

Answer 1

Answer:

(2i.4i) +(3j. 5j)

the vectors are mutually perpendicular so, i×i = 1

and similarly, j×j=1

the answer is 8 + 15

= 23