solve

Asked by sumahr | 15th Jan, 2010, 07:04: PM

Expert Answer:

Since the two vectors are perpendicular, their dot product is zero.

(a+2b).(5a-4b) = 5a.a - 4a.b + 10b.a - 8b.b = 0 

5 + 6a.b - 8 = 0

6a.b = 3

abcosθ = 1/2 ..................a = b = 1

cosθ = 1/2

θ = 60.

Regards,

Team,

TopperLearning.

Answered by  | 15th Jan, 2010, 09:10: PM

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