Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
Home  >>  CBSE XII  >>  Math  >>  Determinants
0 votes

Evaluate the determinant:$ \begin{vmatrix} 2&4 \\ -5&-1 \end{vmatrix} $

$\begin{array}{1 1} -22 \\ 18 \\ -18 \\ 22 \end{array} $

Can you answer this question?

1 Answer

0 votes
  • $\mid A\mid$ of $\begin{vmatrix}a_{11} & a_{12}\\a_{21} & a_{22}\end{vmatrix}=a_{11}a_{22}-a_{21}a_{12}$
  • To evaluate the value of the given determinants ,let us multiply the elements $a_{11}$ and $a_{22}$ and then subtract $a_{21}\times a_{12}$.
Given:Evaluate:$\begin{vmatrix}2 & 4\\-5 & -1\end{vmatrix}$
To evaluate this we know we will have to multiply the elements of the first diagonal and subtract with the elements multiplied along the other diagonal,since it is of order two.
Here $a_{11}=2$
Therefore $\mid A\mid=2\times -1-(-5)\times 4.$


answered Feb 20, 2013 by sreemathi.v
edited Feb 24, 2013 by vijayalakshmi_ramakrishnans
Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App