Question

Find the acute angle between the X-axis and the line joining points A(3, −1) and B(4, −2).

Answer 1

Given: A(3, −1) and B(4, −2)

∴ Slope of line AB = m = `(-2 - ( - 1))/(4 - 3)`

= `(-2 + 1)/1`

= − 1

Let θ be the acute angle between the X-axis and the line AB.

∴ m = tan θ, which is positive

∴ tan θ = |− 1| = 1 = tan 45°

∴ θ = 45°