Determinants · Mathematics · Class 12

If $A$ is a square matrix of order 3 such that the value of $\mid$ adj. $A \mid=8$, then the value of $\left|\mathrm{A}^{\mathrm{T}}\right|$ is

If inverse of matrix $\left[\begin{array}{ccc}7 & -3 & -3 \\ -1 & 1 & 0 \\ -1 & 0 & 1\end{array}\right]$ is the matrix $\left[\begin{array}{lll}1 & 3 & 3 \\ 1 & \lambda & 3 \\ 1 & 3 & 4\end{array}\right]$ then value of $\lambda$ is

$$\text { If }\left|\begin{array}{lll} \alpha & 3 & 4 \\ 1 & 2 & 1 \\ 1 & 4 & 1 \end{array}\right|=0 \text {, then the value of } \alpha \text { is: }$$

Case Study II

Gautam buys 5 pens, 3 bags and 1 instrument box and pays a sum of ₹ 160. From the same shop. Vikram buys 2 pens, 1 bag and 3 instrument boxes and pays a sum of ₹ 190. Also Ankur buys 1 pen, 2 bags and 4 instrument boxes and pays a sum of ₹ 250 .

Based on the above information, answer the following questions:

(i) Convert the given above situation into a matrix equation of the form $$A X=B$$.

(ii) Find $$|\mathrm{A}|$$.

(iii) Find $$\mathrm{A}^{-1}$$.

OR

(iii) Determine $$P=A^2-5 A$$.