Linear Algebra and Its Applications · Problem 1.3.12

Matrices and Gaussian Elimination — Gilbert Strang

Mathematics · gaussian-elimination

Problem

Which number

d

forces a row exchange, and what is the triangular system (not singular) for that

d

? Which

d

makes this system singular (no third pivot)?

\begin{aligned} 2x + 5y + z &= 0 \\ 4x + dy + z &= 2 \\ y - z &= 3. \end{aligned}