- Home
- Standard 12
- Mathematics
3 and 4 .Determinants and Matrices
hard
समीकरण $\left|\begin{array}{ccc}x & -6 & -1 \\ 2 & -3 x & x-3 \\ -3 & 2 x & x+2\end{array}\right|=0$, के वास्तविक मूलों का योगफल है
A
$-4$
B
$0$
C
$6$
D
$1$
(JEE MAIN-2019)
Solution
By expansion, we get
$ – 5{x^3} + 30x – 30 + 5x = 0$
$ \Rightarrow – 5{x^3} + 35x – 30 = 0$
$ \Rightarrow {x^3} – 7x + 6 = 0$, All roots srea real
So, sum of roots $=0$
Standard 12
Mathematics