Question

If A = $\left| \begin{matrix}

• a^{2} & ab & ac \ ab & - b^{2} & bc \ ac & bc & - c^{2} \end{matrix} \right|$, then det. A is

• A. 4 abc
• B. 4a²b²c²
• C. – 4abc
• D. – 4a²b²c²

Answer 1

Answer: (B)

4a²b²c²

Answer 2

det. A = a²b²c² $\left| \begin{matrix}

• 1 & 1 & 1 \ 1 & - 1 & 1 \ 1 & 1 & - 1 \end{matrix} \right|$

= a²b²c²[–1(0) – 1(–2) + 1(2)] = 4a²b²c²