Posted by Cathy on Sunday, June 23, 2013 at 6:19am.
A=[5,-6.5]
B=[-3.5,7]
If A is perpendicular to C, then A.C=0, or
C=[6.5k, 5k]
(verify that A.C=0)
If in addition, C.B=15, we have
C.B=[6.5k,5k].[-3.5,7]
=35k-22.75k
=12.25k
But C.B=15, therefore 12.25k=15, =>
k=15/12.25=60/49
Therefore
C=[6.5k,5k]
=[390/49, 300/49]
Check my arithmetic and that the given conditions are satisfied.
thanks
you're welcome!
I don't understand the flow in the math here. Please help me understand this solution by "dumbing it down" a bit.