Mathematics - Online Test

Q1. A student was asked to prove a statement P ( n ) by method of induction . He proved that P ( 3 ) is true and that P(n)⇒P(n+1) for all natural numbers n . On the basis of this the criteria applied on n for P ( n ) to be true
Answer : Option A
Explaination / Solution:

Since by the principle of mathematical induction if p( n ) is true for n = 3 then that will be the minimum point to be considered for the process.Also that P ( n ) ⇒P(n+1)

Q2.  is equal to
Answer : Option B
Explaination / Solution:



( using L’Hospital Rule)


Q3. The value of k, such that the equation   represents a point circle, is
Answer : Option B
Explaination / Solution:


which gives radius  for a point circle radius should be zero.
hence 
solving which we get k=

Q4. Determine order and degree (if defined) ofcos() = 0
Answer : Option B
Explaination / Solution:

order = 2, degree not defined, because the function dy/dx present in angle of cosine function.

Q5. A fair dice is rolled n times. The number of all the possible outcomes is
Answer : Option C
Explaination / Solution:

each time there are 6 possibilities, therefore for n times there are 6n  possibilities.

Q6.
Equation of a line through a point  and having direction cosines l, m, n is

Answer : Option A
Explaination / Solution:

Equation of a line through a point (x1, y1, z1) and having direction cosines l, m, n is given by : 

Q7. If then cot B + cot C - cot A =
Answer : Option C
Explaination / Solution:



Q8. The area of the region between the curve y = 4 –  and the x –axis is equal to
Answer : Option B
Explaination / Solution:

 y =   And  
Required area:
 =  =

Q9. The equation xy = 0 in three dimensional space represents
Answer : Option B
Explaination / Solution:

since xy=0 implies x=0 or y=0.i.e YZ plane or XZ plane.Hence it represents a pair of planes at right angles

Q10. A square matrix A is called idempotent if
Answer : Option C
Explaination / Solution:

If the product of any square matrix with itself is the matrix itself , then the matrix is called Idempotent.