Mathematics - Online Test

Q1. The points ( 4,7 ,8) ,( 2, 3,4 ),( - 1 , -2 , 1 ) and (1 , 2, 5 ) are the vertices of a
Answer : Option A
Explaination / Solution:

The vertices of a quadrilateral are A( 4,7 ,8) , B( 2, 3,4 ) ,C (- 1 , -2 , 1 ) and D(1 , 2, 5 ) 

Here opposite sides of quadrilateral ABCD are equal , so  it may be parallelogram or rectangle

Here length of diagonals AC and BD are different so ABCD is a parrallelogram

Q2. If a matrix A is symmetric as well as skew symmetric then A is a
Answer : Option B
Explaination / Solution:


Only a null matrix can be symmetric as well as skew symmetric.

In Symmetric Matrix A=A,

    Skew Symmetric Matrix A= -A,

    Given that the matrix is satisfying both the properties therefore Equating the RHS we get A= -A i.e 2A=0 .

   Therefore A=0,which is a null matrix.


Q3. Let f (x) =  then f (x) is decreasing in
Answer : Option B
Explaination / Solution:

Here ,

Q4. Let A and B be two sets in the universal set . Then A - B is equal to
Answer : Option D
Explaination / Solution:



Q5. The inequality | z − 6 | < | z − 2 | represents the region given by
Answer : Option A
Explaination / Solution:



Q6.
Answer : Option B
Explaination / Solution:



Q7. If  is non real cube root of unity , then  
Answer : Option B
Explaination / Solution:

expanding along R

 

 


Q8. The coefficients of  and  ( p, q are + ve integers) in the binomial expansion of  are
Answer : Option B
Explaination / Solution:



Q9. What is the solution set for  ?
Answer : Option D
Explaination / Solution:




Q10.  is equal to
Answer : Option D
Explaination / Solution:

Since the limit is in the form of 0/0. By applying L'hospital first time we get, 

Again using L'Hospital; 

Again using L'Hospital we get