Question

If ||u||= 4 , ||v||=3 and u*v = 3, find ||u+2v||

Answer 1

||4+2(3)||
||2.3=6||
||4+6||
||10||= |10|
|10|= 10
hope that helps

Answer 2

the magnitude of u + 2v is only 10 if u and v are parallel in the same direction

Answer 3

we can find the cos(a) to know how u and v relate to each other since:
\[cos(a)=\frac{u.v}{|u||v|}\]