3 and 4 .Determinants and Matrices
normal

If $a\, -\, 2b + c = 1$ , then value of $\left| {\begin{array}{*{20}{c}}
  {x + 1}&{x + 2}&{x + a} \\ 
  {x + 2}&{x + 3}&{x + b} \\ 
  {x + 3}&{x + 4}&{x + c} 
\end{array}} \right|$ is

A

$x$

B

$-x$

C

$-1$

D

$1$

Solution

$\mathrm{R}_{1} \rightarrow \mathrm{R}_{1}-2 \mathrm{R}_{2}+\mathrm{R}_{3}$

$\left|\begin{array}{ccc}{0} & {0} & {1} \\ {\mathrm{x}+2} & {\mathrm{x}+3} & {\mathrm{x}+\mathrm{b}} \\ {\mathrm{x}+3} & {\mathrm{x}+4} & {\mathrm{x}+\mathrm{c}}\end{array}\right|$

$\mathrm{R}_{3} \rightarrow \mathrm{R}_{3}-\mathrm{R}_{2} \Rightarrow \Delta=-1$

Standard 12
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.