Determinants - Online Test
Q1. Find the area of triangle with vertices ( 1 ,1 ) , (2 ,2 ) and ( 3, 3 ).
Answer : Option C
Explaination / Solution:
AREA OF TRIANGLE= 
That is C1 and C2 are identical
so value of determinant =0
hence area of triangle =0
Q2. Find the area of triangle with vertices ( 0 ,0 ),(4 , 2) and ( 1,1).
Answer : Option D
Explaination / Solution:
Q3. A(adj A) is equal to
Answer : Option C
Explaination / Solution:
Since, we know that
pre multiply by A,
(since AA-1=)
Q4. The inverse of the matrix A = 
Answer : Option C
Explaination / Solution:
Q5. If A and B are invertible matrices of order 3 , then det(adj A) =
Answer : Option C
Explaination / Solution:
Let A be a non singular square matrix of order n then
det(adjA)=|A|n-1
here order is 3 so det(adj A)=|A|3-1=|A|2
Q6. If A is a square matrix of order 2 , then det (adj A) =
Answer : Option C
Explaination / Solution:
Let A be a square matrix of order 2 then , because where n is the order of square matrix.
Q7. If A is a non singular matrix of order 3 , then =
Answer : Option A
Explaination / Solution:
If A is anon singular matrix of order , then =
Q8. If is the identity matrix of order 3 , then is
Answer : Option C
Explaination / Solution:
Because , the inverse of an identity matrix is an identity matrix itself.
Q9. The roots of the equation 
Answer : Option C
Explaination / Solution:
Q10. The value of det A where A= 
lies in the interval
lies in the interval
Answer : Option D
Explaination / Solution:
