Vector u has a magnitude of 5 units, and vector v has a magnitude of 4 units. Which of these values are possible for the magnitude of u + v?

I believe there are more than one answers:

A: 1 Unit
B: 9 units
C: 11 Units
D: 13 Units

1 answer

If they have the same direction, then their magnitude is 9
It is also possible to have a triangle with sides 4,5, and 1
clearly not with sides 11 or 13

so A and B