Q2 of 319 Page 24

Find the acute angle between the lines 2x – y + 3 = 0 and x + y + 2 = 0.

Given:


The equations of the lines are


2x − y + 3 = 0 … (1)


x + y + 2 = 0 … (2)


To find:


Angles between two lines.


Explanation:


Let m1 and m2 be the slopes of these lines.


m1 = 2, m2 = -1


Let θ be the angle between the lines.
Then,



⇒


Hence, the acute angle between the lines is


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