Question

Find the angle between the two vectors given by A= 3i+ k and B=j+4​

Answer 1

Explanation:

here we will use dot product

A.B = IAIIBI cos(x) , where x is the angl

now, a.b = (3i + k).(j+4k) since the question is wrong, as 4 should have i, j or k , so I am taking it as k, you may follow the same method as in answer if some other alphabet is there

= 3i.j + 12i.k + j.k + 4k.k = 0+0+0+4 = 4

so, 4 = 10 × ✓17 cos(x)

so x = cos^-1(4/10√17)