The GATE Grind

GATE 2025 MA – Question 37

Ordinary Differential Equations · Higher Order Equations and Systems · 2 marks · Multiple choice

x²y″+7xy′+9y=x⁻³ ln x for x>0, with y(1)=y′(1)=0. Find y(e).

  1. $e^{-3}/3$
  2. $e^{-3}/6$
  3. $2e^{-3}/3$
  4. $e^{-3}/2$

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (B) $e^{-3}/6$

Explanation

Put t=lnx. The Euler operator becomes $(D_t+3)^2y=e^{-3t}t$. Write y=e⁻³ᵗv(t), giving v″=t. Initial conditions imply v(0)=v′(0)=0, so v=t³/6. At x=e,t=1, **y=e⁻³/6, B**.

More Higher Order Equations and Systems questions

All Higher Order Equations and Systems questions →