Example 18 - Find equation of tangent at point where it cuts

Example 18 - Chapter 6 Class 12 Application of Derivatives - Part 2
Example 18 - Chapter 6 Class 12 Application of Derivatives - Part 3
Example 18 - Chapter 6 Class 12 Application of Derivatives - Part 4

Take a fresh quiz. Then take another.
Every attempt is a new AI-adaptive Teachoo quiz with 2 questions, selected from your answers, mistakes, and progress.
Remove Ads Share on WhatsApp

Transcript

Question 5 Find the equation of the tangent to the curve y = (š‘„ āˆ’ 7)/((š‘„ āˆ’ 2)(š‘„ āˆ’ 3)) at the point where it cuts the x-axis.Slope of the tangent to the curve is š‘‘š‘¦/š‘‘š‘„ = ((š‘„ āˆ’ 7)^′ [(š‘„ āˆ’ 2) (š‘„ āˆ’ 3)]āˆ’ (š‘„ āˆ’ 7) [(š‘„ āˆ’ 3) (š‘„ āˆ’ 2)]^′)/((š‘„ āˆ’ 2)^2 (š‘„ āˆ’ 3)^2 ) š‘‘š‘¦/š‘‘š‘„ = (1 Ɨ (š‘„ āˆ’ 2) (š‘„ āˆ’ 3) āˆ’ (š‘„ āˆ’ 7)[(š‘„ āˆ’ 3)^′ (š‘„ āˆ’ 2) + (š‘„ āˆ’ 3) (š‘„ āˆ’ 2)^′ ])/((š‘„ āˆ’ 2)^2 (š‘„ āˆ’ 3)^2 ) š‘‘š‘¦/š‘‘š‘„ = ((1) (š‘„ āˆ’ 2) (š‘„ āˆ’ 3) āˆ’ (š‘„ āˆ’ 7)[1 Ɨ (š‘„ āˆ’ 2) + (š‘„ āˆ’ 3) Ɨ 1])/((š‘„ āˆ’ 2)^2 (š‘„ āˆ’ 3)^2 ) š‘‘š‘¦/š‘‘š‘„ = ((š‘„ āˆ’ 2) (š‘„ āˆ’ 3) āˆ’ (š‘„ āˆ’ 7)(2š‘„ āˆ’ 5))/((š‘„ āˆ’ 2)^2 (š‘„ āˆ’ 3)^2 ) š‘‘š‘¦/š‘‘š‘„ = ((š‘„ āˆ’ 2) (š‘„ āˆ’ 3) )/((š‘„ āˆ’ 2)^2 (š‘„ āˆ’ 3)^2 )āˆ’(š‘„ āˆ’ 7)(2š‘„ āˆ’ 5)/((š‘„ āˆ’ 2)^2 (š‘„ āˆ’ 3)^2 ) š‘‘š‘¦/š‘‘š‘„ = (1 )/((š‘„ āˆ’ 2) (š‘„ āˆ’ 3) )āˆ’((š‘„ āˆ’ 7))/((š‘„ āˆ’ 2) (š‘„ āˆ’ 3) ) Ɨ ((2š‘„ āˆ’ 5))/((š‘„ āˆ’ 2) (š‘„ āˆ’ 3) ) š‘‘š‘¦/š‘‘š‘„ = (1 )/((š‘„ āˆ’ 2) (š‘„ āˆ’ 3) )āˆ’š‘¦ Ɨ ((2š‘„ āˆ’ 5))/((š‘„ āˆ’ 2) (š‘„ āˆ’ 3) ) š’…š’š/š’…š’™ = (šŸ āˆ’ š’š(šŸš’™ āˆ’ šŸ“))/((š’™ āˆ’ šŸ) (š’™ āˆ’ šŸ‘) ) We need to find Equation of tangent at the point where the curve cuts the x axis, Thus, y = 0 We need to find value of x Putting y = 0 in equation of curve 0 = (š‘„ āˆ’ 7)/(š‘„ āˆ’ 2)(š‘„ āˆ’ 3) ∓ x = 7 Thus, curve cuts the x-axis at point (7, 0) Finding Slope at point (7, 0) š‘‘š‘¦/š‘‘š‘„ = (1 āˆ’ š‘¦(2š‘„ āˆ’ 5))/((š‘„ āˆ’ 2) (š‘„ āˆ’ 3) ) Putting x = 7, y = 0 = (1 āˆ’ 0[2(7)āˆ’5])/((7 āˆ’ 2) (7 āˆ’ 3) ) = 1/(5 Ɨ 4) = šŸ/šŸšŸŽ Now, Equation of the tangent at point (7, 0) with slope 1/20 is š‘¦ āˆ’š‘¦_1= š‘š (š‘„ āˆ’ š‘„1) š‘¦āˆ’0= 1/20 (š‘„āˆ’7) 20š‘¦=š‘„āˆ’7 šŸšŸŽš’šāˆ’š’™+šŸ•=šŸŽ

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 14 years. He provides courses for Maths, Science and Computer Science at Teachoo