Question

The angle substended by vector A=4i+3J+12K with the x axis is

Answer 1

Answer:72.1 degree

Explanation:

The vector on the x axis is U(x) = (1, 0, 0)

Vector A = (4, 3, 12)

Use DOT product and inverse Cosine to find the angle.

A dot U =IIAII IIUII cos(angle between them)

Angle between them = cos^-1 { (A dot U) / (IIAII IIUII) }

IIAII = 13

IIUII = 1

A dot U = 4

Angle = cos^-1 (4/13) = 72.1 degree