Help with vector dot product?If a and b are vectors such that |a| = 3 and |b| = 2 and the angle between a and b is pi/3
evaluate (a+b) dot (a+b)
i expanded the brackets and got a.a+a.b+b.a+b.b and simplified it to 2(a.b)
and then evaluated it as 2(3x2xcos(pi/3))
which gave me 6, but the answers say 19 :/
Thanks for your help :)
0 коммент.:
Post a Comment