UPSC NDA Math Model Paper 9

Here, we have to find the angle between the lines whose slopes are 1/2 and 3
Let m1=1∕2 and m2=3
As we know that, tan‌α=|

m2−m1

1+m1.m2

|
⇒tan‌α=|

3− 1 2

1+ 1 2 .3

|=1
⇒α = 45°
So, the angle between the lines whose slopes are 1/2 and 3 is 45°
Hence, option D is the correct answer.