Question

find the
acute angle between the
lines having slope -1/3 & -2,​

Answer 1

acute angle = 0 to 90 degree

but you have fraction is negative so it can be acute angle

Answer 2

Answer:

let the acute angle be θ and the slope of lines be m1 = -1/3 and m2 = -2.

by the formula,

→$\tan(θ) = \frac{m1 - m2}{1 + m1m2}$

→$\tan(θ) = \frac{ (\frac{ - 1}{3}) - ( - 2) }{1 + ( \frac{ - 1}{3})( - 2) }$

→$\tan(θ) = \frac{ \frac{ - 1}{3} + 2 }{1 + \frac{2}{3} }$

→$\tan(θ) = \frac{ \frac{ - 1 + 6}{3} }{ \frac{3 + 2}{3} }$

→$\tan(θ) = \frac{ \frac{5}{3} }{ \frac{5}{3} }$

→$\tan(θ) = 1$

$so, \: θ = \frac{ \pi}{4}$