MCQ
The determinant $\left| {\,\begin{array}{*{20}{c}}a&b&{a - b}\\b&c&{b - c}\\2&1&0\end{array}\,} \right|$ is equal to zero if $a,b,c$ are in
  • $G. P.$
  • B
    $A. P.$
  • C
    $H. P.$
  • D
    None of these

Answer

Correct option: A.
$G. P.$
a
(a) On expanding, $ - a(b - c) + 2b(b - c) + (a - b)(b - 2c) = 0$

==> $ - ab + ac + 2{b^2} - 2bc + ab - 2ac - {b^2} + 2bc = 0$

==> ${b^2} - ac = 0$

==> ${b^2} = ac$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $0 \le x < 2\pi $ , then the number of real values of $x,$ which satisfy the equation  $\cos x + \cos 2x + \cos 3x + \cos 4x = 0$ is  . .  .
If the product of three consecutive terms of $G.P.$ is $216$  and the sum of product of pair-wise is $156$, then the numbers will be
The sum of all real values of $x$ satisfying the equation ${\left( {{x^2} - 5x + 5} \right)^{{x^2} + 4x - 60}} = 1$ is ;
The interior angle of a $'n$' sided convex polygon are in $G.P$.. The smallest angle is $1^o $ and common ratio is $2^o $ then number of possible values of $'n'$ is
Let $I(x)=\int \frac{(x+1)}{x\left(1+x e^x\right)^2} d x, x > 0$, If $\lim _{x \rightarrow \infty} I(x)=0$, then $I(1)$ is equal to
If $y\, = mx + c$ is the normal at a point on the parabola $y^2\, = 8x$ whose focal distance is $8\, units$, then $\left| c \right|$ is equal to
Let $A \equiv \left( {4,4} \right),\,B \equiv \left( {8,4} \right),\,C \equiv \left( {4,8} \right)$ . If $P,Q,R$ are the midpoint of sides $AB,BC$ & $CA$ respectively & $(\alpha ,\beta )$ be the co-ordinates of orthocentre of $\Delta PQR$ , then the value of $\alpha  + \beta $ is
$\int_{}^{} {{{\sin }^{ - 1}}(3x - 4{x^3})dx = } $
If $m$ is the $A.M$ of two distinct real numbers $ l$  and $n (l,n>1) $ and  $G_1, G_2$ and $G_3$ are three geometric means between  $l$ and $n$ then $G_1^4 + 2G_2^4 + G_3^4$ equals :
For each positive integer $n$, let $y _{ n }=\frac{1}{ n }(( n +1)( n +2) \ldots( n + n ))^{\frac{1}{n}}$.

For $x \in R$, let $[x]$ be the greatest integer less than or equal to $x$. If $\lim _{n \rightarrow \infty} y_n=L$, then the value of $[ L ]$ is. . . . . . . .