Mathematics - Online Test

Q1. If f(x) = then
Answer : Option C
Explaination / Solution:

,therefore , f is neither continuous nor differentiable at x = 0

Q2. S and T are the foci of an ellipse and B is an end of the minor axis. If STB is an equilateral triangle, the eccentricity of the ellipse is
Answer : Option B
Explaination / Solution:

s = (ae,0) and T = (-ae,0) and B = (0,b)

Since it is an equilateral triangle, ST2 = TB2

This implies 4a2e2 = a2e2 + b2

3a2e2 = b

3a2e2 = a2(1 - e2)

3e2  = 1 - e2

Therefore e = 1/2


Q3. The smallest positive integer n , for which  holds :
Answer : Option C
Explaination / Solution:

When n = 1 we get ,which is invalid. When n = 2 we get, which is valid.

Q4. If sin  = 2, then 
Answer : Option D
Explaination / Solution:



Q5. Find the shortest distance between the lines  
Answer : Option D
Explaination / Solution:



Q6. The number of ways in which the 6 faces of a cube can be painted with 6 different colours is
Answer : Option C
Explaination / Solution:

We have a cube has 6  faces and we have to colour it with 6 different colours .

Then  the no of ways of colouring ==720, but in this we will be getting  many overcountings.

 We have there are 24 ways in which we can orient a cube 

 Hence the number of distinct ways of colouring a cube with 6 different colours is 
 


Q7. Skew lines are
Answer : Option D
Explaination / Solution:

Skew lines are those lines which lie in different planes and never meet

Q8. If for a matrix A, where I is the identity matrix, then A equals
Answer : Option D
Explaination / Solution:





Q9. General solution of is
Answer : Option C
Explaination / Solution:



Q10.  is
Answer : Option B
Explaination / Solution: