Check sibling questions

Ex 6.4, 1 (xii) - Find approximate value upto 3 decimals - (26.57)^1/3

Ex 6.4, 1 (xii) - Chapter 6 Class 12 Application of Derivatives - Part 2
Ex 6.4, 1 (xii) - Chapter 6 Class 12 Application of Derivatives - Part 3

Maths Crash Course - Live lectures + all videos + Real time Doubt solving!


Transcript

Ex 6.4, 1 Using differentials, find the approximate value of each of the following up to 3 places of decimal. (xii) 〖(26.57)〗^(1/3)Let 𝑦=𝑥^( 1/3) where 𝑥=27 & ∆ 𝑥=−0. 43 Now, 𝑦=𝑥^( 1/3) Differentiating w.r.t.𝑥 𝑑𝑦/𝑑𝑥=𝑑(𝑥^( 1/3) )/𝑑𝑥=1/3 𝑥^( 1/3 − 1)=1/3 𝑥^( (− 2)/( 3))=1/(3 𝑥^( 2/( 3)) ) Using ∆𝑦=𝑑𝑦/𝑑𝑥 ∆𝑥 ∆𝑦=1/(3 𝑥^( 2/( 3)) ) × ∆𝑥 Putting Values ∆𝑦=1/(3 (27)^( 2/( 3)) ) × (−0. 43) ∆𝑦=(−0. 43)/(3 × 3^(3 × 2/( 3)) ) ∆𝑦=(−0. 43)/(3 × 3^2 ) ∆𝑦=(−0. 43)/(3 × 9) ∆𝑦=(−0. 43)/27 ∆𝑦=−0. 015926 We know that ∆𝑦=𝑓(𝑥+∆𝑥)−𝑓(𝑥) So, ∆𝑦=〖(𝑥+∆𝑥) 〗^(1/3)−𝑥^( 1/3) Putting Values −0. 015926=(27+(−0. 43))^( 1/3)−(27)^( 1/3) −0. 015926=(26. 57)^( 1/3)−(27)^( 3 × 1/3) −0. 015926=(26. 57)^( 1/3)−3 −0. 015926+3=(26. 53)^( 1/3) 2. 984=(26. 53)^( 1/3) Thus, the Approximate Values of (26. 53)^( 1/3) is 𝟐. 𝟗𝟖𝟒

Ask a doubt (live)
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 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.