Last updated at Dec. 8, 2016 by Teachoo

Transcript

Example 2 If the angle between two lines is ๐/4 and slope of one of the lines is 1/2 , find the slope of the other line. We know that angle between two lines are tan ฮธ = |(๐2 โ ๐1)/(1 + ๐1๐2)| Putting ฮธ = ๐/4 = 180/4 = 45ยฐ Let m1 and m2 be the slope of 2 lines So, m1 = 1/2 We need to find slope of 2nd line i.e. m2 Putting values in formula tan ฮธ = |(๐2 โ ๐1)/(1 + ๐1๐2)| tan 45ยฐ = |(๐2 โ 1/2)/(1 + 1/2 ๐2)| 1 = |((2๐_2 โ 1)/2)/((2 +๐_2)/2)| 1 = |(2๐2 โ 1)/(2 + ๐2)| |(2๐2 โ 1)/(2 + ๐2)|= 1 So, (2๐2 โ 1)/(2 + ๐2) = 1 & (2๐2 โ 1)/(2 + ๐2) = โ 1 Therefore m2 = 3 or m2 = (โ1)/3 . Hence, Slope of the other line is 3 or (โ1)/3

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.