Ex 10.2, 9 - Vertices of PQR are P (2, 1), Q (-2, 3), R (4, 5)

Ex 10.2, 9 - Chapter 10 Class 11 Straight Lines - Part 2
Ex 10.2, 9 - Chapter 10 Class 11 Straight Lines - Part 3

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class


Transcript

Ex 9.2, 8 The vertices of ΔPQR are P (2, 1), Q (–2, 3) and R (4, 5). Find equation of the median through the vertex R. Vertices are P (2, 1), Q (–2, 3), and R (4, 5). We need to find equation of median i.e. Equation of RS Since RS is median, S is the mid point of PQ We know that mid point of a line joining points (x1, y1) & (x2, y2) is ((𝑥1 + 𝑥2 )/2, (𝑦1 + 𝑦2)/2) Mid-point QR passing through (2, 1) & (−2, 3) S = ((2 + ( −2))/2,(1 + 3)/2) S = ((2 − 2)/2,4/2) S = (0, 2) Now we need to find equation of line passing through R (4, 5) & S (0, 2) We know that equation of line through two points (x1, y1) & (x2, y2) is y – y1 = (𝑦_2 − 𝑦_1)/(𝑥_2 − 𝑥_1 ) (x – x1) Putting values (y – 5) = (2 − 5)/(0 − 4) (x – 4) y – 5 = ( −3)/( −4) (x – 4) y – 5 = 3/4 (x – 4) 4 (y – 5) = 3 (x – 4) 4y – 20 = 3x – 12 4y – 3x = 3x – 12 4y – 3x – 20 + 12 = 0 4y – 3x – 8 = 0 3x – 4y + 8 = 0 Hence equation of median is 3x – 4y + 8 = 0

Ask a doubt
Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.