Vectors

I’m doing question 16



I’m alright with it until part c. I can do it but I’m confused with the solution given



I got the values of lambda as per solution but what is Lamda = 1 for C and -1 for D. Could it have been the other way round. That’s the only bit I’m struggling to grasp

Thanks

Whichever way round it is, the midpoint is the same, so just P (lambda=0)

I would have used Mu as the parameter for line 2 since lambda is used for line 1.
So I end up with Mu=1 or Mu=-1 ... these will correspond to the 2 points C and D on line 2 which satisfy AB=AC=AD.
Could write it the other way round.

Yes, thanks. It's just that the solution appeared to be specific that Lamda = 1 for C. There was no "it doesn't matter" indicated.