Points A, B and C lie on the line r = 2i + 3j + λ(i + 4j) and have position vectors given by λ=-1, λ=1 and λ=2 respectively.(adsbygoogle = window.adsbygoogle || []).push({});

Find a) AB

b) AB:BC

The answer for part a is the square root of 17 (in exact form) however I keep getting the suare root of 20.

Here is what I am doing:

OB = 3i – j and OC = 5i – 5j

BC= BO + OC

BC= -(3i – j) + (5i – 5j)

BC= 2i – 4j

Therefore the magnitude of BC = square root of 20

As for part b, I’m not sure what it’s asking me to do

Thanks

Pavadrin

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# Homework Help: Vector equation of a line

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