Mathematics - Online Test

Q1.  dx is equal to
Answer : Option A
Explaination / Solution:

cos((xa)+a)cos(xa)dx=cos(xa)cosasin(xa)sinacos(xa)dx={cosasinatan(xa)}dx.xcosa+sinalog|cos(xa)|+C
Q2. In the figure which are the Equal vectors?

Answer : Option B
Explaination / Solution:

 are equal vectors , because they have equal magnitude and same direction.

Q3. If P (A) = 0.8, P (B) = 0.5 and P(B|A) = 0.4, find P(A|B)
Answer : Option B
Explaination / Solution:

We have ,
P (A) = 0.8, P (B) = 0.5 and P(B|A) = 0.4


Q4. If  then  is equal to
Answer : Option C
Explaination / Solution:


sin1x+cos1x=π2cos1x=π2sin1x=π2π5=3π10.

Q5. If f(x) = then
Answer : Option C
Explaination / Solution:

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

Q6. 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


Q7. 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.

Q8. If sin  = 2, then 
Answer : Option D
Explaination / Solution:



Q9. Find the shortest distance between the lines  
Answer : Option D
Explaination / Solution:



Q10. 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