Test Index

CBSE Class 12 Math 2020 Delhi Set 2 Solved Paper

Show Para  Hide Para 
Note : Except for the following questions, all the remaining questions have been asked in the previous sets.
© examsnet.com
Question : 1 of 11
Marks: +1, -0
If [x1][10−20]=0\begin{bmatrix} x & 1 \end{bmatrix} \begin{bmatrix} 1 & 0 \\ -2 & 0 \end{bmatrix} = 0, then xx equals
Solution:  
  [x1][10−20]  =0\;\begin{bmatrix} x & 1 \end{bmatrix} \begin{bmatrix} 1 & 0 \\ -2 & 0 \end{bmatrix}\;=0
  \;
⇒  [x−20]  =[00]\Rightarrow\; \begin{bmatrix} x-2 & 0 \end{bmatrix}\; = \begin{bmatrix} 0 & 0 \end{bmatrix}
⇒x−2  =0\Rightarrow x-2\;=0
⇒  x  =2\Rightarrow\; x\; =2
  ∴  Option (d) is correct.    \; \therefore \; \text{Option (d) is correct.}\;\;
© examsnet.com
Go to Question:
Next Question