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GATE 2025 BM – Question 39

Engineering Mathematics · Differential Equations · 2 marks · Multiple choice

y″−0.25y=0 with y(0)=1,y′(0)=1. Find y(ln100).

  1. 14.05
  2. 14.25
  3. 14.95
  4. 14.65

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Correct answer: (C) 14.95

Explanation

The general solution is Ae^(x/2)+Be^(−x/2). Initial conditions give A+B=1 and (A−B)/2=1, hence A=1.5,B=−0.5. At x=ln100, the exponentials are ten and one tenth, so y=15−0.05=14.95, C.

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