Question

The angle subtended by the vector A Bar is equalI to 4 I CAP + 3 J cap + 12 K cap with the x-axis is

Answer 1

Given, 4i+3j+12k

let the point on x axis be (1,0,0)

Use DOT product and inverse Cosine to find the angle.

Angle = cos^-1(A.U/|A|.|U|)

A.U=4

|A|=13 |U|=1

Angle= cos^-1(4/13) =72.07 degrees