Given the line y = 3x, find the sine value of the angle (acute angle) between the line and X axis

Given the line y = 3x, find the sine value of the angle (acute angle) between the line and X axis

Straight line y = 3x passing through origin o (0,0)
Passing point a (1,3)
Make the vertical ab of X axis through point a
Then AB = 3, OB = 1
According to Pythagorean theorem, OA = √ 10
Then sin ∠ AOB = AB / OA = 3 / √ 10 = (3 √ 10) / 10