GATE AG 2015 • Q36 NAT • 2 Marks

Section 3: Farm Power

Farm Power

Subtopic: Thermodynamic principles of I.C. engines

Question Statement:

Values of the function y = 1/(1+x²) are y(0)=1; y(1)=0.5; y(2)=0.2; y(3)=0.1; y(4)=0.0588; y(5)=0.0385; y(6)=0.027. Using Simpson's one-third rule, the value of the integral ∫₀⁶ dx/(1+x²) is _____.

Official Answer Key:

1.35 to 1.40

Step-by-Step Solution & Explanation

Simpson's 1/3 rule with h = 1 and 6 equal intervals (7 ordinates y₀…y₆): ∫ ≈ (h/3)×[(y₀+y₆) + 4(y₁+y₃+y₅) + 2(y₂+y₄)] = (1/3)×[(1+0.027) + 4(0.5+0.1+0.0385) + 2(0.2+0.0588)] = (1/3)×[1.027 + 4(0.6385) + 2(0.2588)] = (1/3)×[1.027 + 2.554 + 0.5176] = (1/3)× 4.0986 = 1.366. This lies within the accepted range 1.35–1.40. (The exact analytical value, tan⁻¹(6) = 1.4056 rad, is slightly higher — the Simpson approximation under-estimates it slightly because the tabulated y-values were themselves rounded.)

Practice This in Real CBT Exam Interface

Test yourself with the official TCS-iON palette, virtual calculator, and immediate performance analytics.

Launch CBT Mock Test