Mathematics - Online Test

Q1.
Answer : Option A
Explaination / Solution:

The tangents are
since .
It passes through ( -2 , 0 ).

The tangents are :

Required area :

Q2. If a unit vector  makes angles , then find 
Answer : Option C
Explaination / Solution:

Let

It is given that   

, then,

Putting these values in (1), we get:


Q3. If f (x) = f (a –x), then ,  is equal to
Answer : Option C
Explaination / Solution:



Q4. cos(cos1(725))=
Answer : Option D
Explaination / Solution:



Q5. The line y = m x + c, touches the parabola  if
Answer : Option D
Explaination / Solution:

y = m x + c ---(i)

 ---(ii)

putting the value of y from (i) in (ii), we get

=> 

here

discriminant =

                     =

when discriminant >0 line touches parabola at two points,

when discriminant < 0 line do not  touches parabola and

when discriminant = 0 line touches parabola at one point

and we know that tangent is a line that touches the curve at exactly one point

so putting discriminat = 0 and solving

we get 

 

 

on putting the value of y from line in the parabola and solving for equal roots.


Q6.

If  sinα=sinβ and cosα=cosβ , then


Answer : Option A
Explaination / Solution:



Q7. For all n  N , is divisible by
Answer : Option A
Explaination / Solution:

Replace n = 1 , we have 64.

Q8. If A and B are two mutually exclusive events, then P (A + B) is equal to
Answer : Option C
Explaination / Solution:
No Explaination.


Q9. The points A ( 0 , 0 , 0 ) , B ( 1 ,  , 0 ) , C ( 2 , 0 , 0 ) and D ( 1 , 0 , ) are the vertices of
Answer : Option B
Explaination / Solution:
No Explaination.


Q10. The equations, x + 4 y – 2 z = 3, 3 x + y + 5 z = 7, 2 x + 3y +z = 5 have
Answer : Option D
Explaination / Solution:

The given system of equations does not have solution if :