Subscribe to our Youtube Channel - https://you.tube/teachoo

Last updated at May 29, 2018 by Teachoo

Transcript

Ex 7.2 , 4 Find the ratio in which the line segment joining the points (– 3, 10) and (6, – 8) is divided by (– 1, 6). Let the points be A(−3, 10) , B(6, −8) , C(−1, 6) We need to find ratio between AC & CB Let the ratio be k : 1 Hence, m1 = k , m2 = 1 x1 = −3 , y1 = 10 x2 = 6 , y2 = −8 & x = −1 , y = 6 Using section formula x = (𝑚_1 𝑥_2+𝑚_2 𝑥_1)/(𝑚_1+𝑚_2 ) −1 = (𝑘 × 6 +1 ×−3)/(𝑘 +1) −1 = (6𝑘 −3)/(𝑘 +1) −1(k + 1)= 6k − 3 −k – 1 = 6k − 3 −k – 6k = −3 + 1 −7k = −2 k = (−2)/(−7) k = 2/7 Hence, the ratio is k : 1 = 2/7 : 1 Multiplying 7 both sides = 7 × 2/7 : 7 × 1 = 2 : 7 So, the ratio is 2: 7

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.