दर्शाइए कि $\left|\begin{array}{ccc}1+a & 1 & 1 \\ 1 & 1+b & 1 \\ 1 & 1 & 1+c\end{array}\right|=a b c\left(1+\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right)=a b c+b c+c a+a b$

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Taking out factors $a, b, c$ common from $\mathrm{R}_{1}, \mathrm{R}_{2}$ and $\mathrm{R}_{3},$ we get

$\text { L.H.S. }=a b c\left|\begin{array}{ccc}
\frac{1}{a}+1 & \frac{1}{a} & \frac{1}{a} \\
\frac{1}{b} & \frac{1}{b}+1 & \frac{1}{b} \\
\frac{1}{c} & \frac{1}{c} & \frac{1}{c}+1
\end{array}\right|$

Applying $\mathrm{R}_{1} \rightarrow \mathrm{R}_{1}+\mathrm{R}_{2}+\mathrm{R}_{3},$ we have

$\Delta=a b c\left|\begin{array}{ccc}
1+\frac{1}{a}+\frac{1}{b}+\frac{1}{c} & 1+\frac{1}{a}+\frac{1}{b}+\frac{1}{c} & 1+\frac{1}{a}+\frac{1}{b}+\frac{1}{c} \\
\frac{1}{b} & \frac{1}{b}+1 & \frac{1}{b} \\
\frac{1}{c} & \frac{1}{c} & \frac{1}{c}+1
\end{array}\right|$

$=a b c\left(1+\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right)\left|\begin{array}{ccc}
1 & 1 & 1 \\
\frac{1}{b} & \frac{1}{b}+1 & \frac{1}{b} \\
\frac{1}{c} & \frac{1}{c} & \frac{1}{c}+1
\end{array}\right|$

Now applying $\mathrm{C}_{2} \rightarrow \mathrm{C}_{2}-\mathrm{C}_{1}, \mathrm{C}_{3} \rightarrow \mathrm{C}_{3}-\mathrm{C}_{1},$ we get

$\Delta  = \operatorname{abc} \left( {1 + \frac{1}{a} + \frac{1}{b} + \frac{1}{c}} \right)\left| {\begin{array}{*{20}{c}}
  1&0&0 \\ 
  {\frac{1}{b}}&1&0 \\ 
  {\frac{1}{c}}&0&1 
\end{array}} \right|$

$ = abc\left( {1 + \frac{1}{a} + \frac{1}{b} + \frac{1}{c}} \right)[1(1 - 0)]$

$ = abc\left( {1 + \frac{1}{a} + \frac{1}{b} + \frac{1}{c}} \right)$

$ = abc + bc + ca + ab = {\text{R}}.{\text{H}}.{\text{S}}$

Similar Questions

समीकरण $\left| {\,\begin{array}{*{20}{c}}{x + \alpha }&\beta &\gamma \\\gamma &{x + \beta }&\alpha \\\alpha &\beta &{x + \gamma }\end{array}\,} \right| = 0$ से प्राप्त $x$ के मान होंगे 

सारणिक का प्रसरण किए बिना सिद्ध कीजिए कि $\left|\begin{array}{lll}a & a^{2} & b c \\ b & b^{2} & c a \\ c & c^{2} & a b\end{array}\right|=\left|\begin{array}{ccc}1 & a^{2} & a^{3} \\ 1 & b^{2} & b^{3} \\ 1 & c^{2} & c^{3}\end{array}\right|$

सारणिक $\left|\begin{array}{ccc}102 & 18 & 36 \\ 1 & 3 & 4 \\ 17 & 3 & 6\end{array}\right|$ का मान ज्ञात कीजिए

सिद्ध कीजिए कि सारणिक

$\Delta=\left|\begin{array}{ccc}
a+b x & c+d x & p+q x \\
a x+b & c x+d & p x+q \\
u & v & w
\end{array}\right|=\left(1-x^{2}\right)\left|\begin{array}{lll}
a & c & p \\
b & d & q \\
u & v & m
\end{array}\right|$

बिना प्रसरण किए और सारणिकों के गुणधर्मो का प्रयोग करके सिद्ध कीजिए।

$\left|\begin{array}{lll}a-b & b-c & c-a \\ b-c & c-a & a-b \\ c-a & a-b & b-c\end{array}\right|=0$