JEE Main 2020 (Online) 3rd September Morning ShiftQuestion 1
If $\Delta=\begin{vmatrix}x-2&2x-3&3x-4\\2x-3&3x-4&4x-5\\3x-5&5x-8&10x-17\end{vmatrix}=Ax^3+Bx^2+Cx+D$, then $B+C$ is equal to :
Determinant
Solution
Expanding the determinant (or using $C_2\to C_2-C_1$, $C_3\to C_3-C_2$ ...) gives $\Delta=-3x^3+12x^2-15x+6$. $B+C=12-15=-3$. Option (A).