The GATE Grind

GATE 2024 MA – Question 21

Numerical Analysis · Linear Systems · 1 mark · Multiple choice

$A=\begin{pmatrix}2&-1&1\\1&2&-1\\-1&1&2\end{pmatrix}$. For (A+εI)x=b, ε>0, I: Jacobi converges for every start. II: Gauss–Seidel converges for every start. Choose truth values.

  1. Both I and II true
  2. I true, II false
  3. I false, II true
  4. Both false

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (A) Both I and II true

Explanation

Each diagonal entry has magnitude 2+ε while the absolute off-diagonal row sum is 2. Strict row diagonal dominance guarantees convergence of both Jacobi and Gauss–Seidel for any initial approximation. **A**.

More Linear Systems questions

All Linear Systems questions →