If y = x4 – 10 and if x changes from 2 to 1.99, what is the change in y

(A)0.32   (B) 0.032   (C) 5.68   (D) 5.968

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Transcript

Question 9 If y = x4 – 10 and if x changes from 2 to 1.99, what is the change in y 0.32 (B) 0.032 (C) 5.68 (D) 5.968 Since, 𝑥 changes from 2 to 1.99 So, ∆𝒙 = 𝒙_𝟐−𝒙_𝟏 = 1.99 − 2 ∆ 𝑥 = − 0.01 Finding 𝒅𝒚/𝒅𝒙 𝑦=𝑥^4−10 𝑑𝑦/𝑑𝑥 = 4𝒙^𝟑 Putting 𝐱=𝟐, as value of 𝑥 changes from 2 𝑑𝑦/𝑑𝑥= 4(2)^3 𝑑𝑦/𝑑𝑥=𝟑𝟐 Now, ∆𝒚 = 𝒅𝒚/𝒅𝒙 ∆𝒙 Putting values of ∆𝑥 = 0.01 and 𝑑𝑦/𝑑𝑥 = 32 ∆𝑦 = 32 (−0.01) ∆𝒚 = 0.32 ∴ Approximate change in 𝑦 is 0.32 So, the correct answer is (A)

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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, Social Science, Physics, Chemistry, Computer Science at Teachoo.