Mathematics - Online Test

Q1. Negation of the statement q∨∼(p∧r) is
Answer : Option C
Explaination / Solution:

∼(q∨∼(p∧r))   Since ∼(q∨r)≡∼q∧∼r
∼q∧(p∧r)

Q2. If ∫ f(x) dx = f (x), then
Answer : Option B
Explaination / Solution:


It implies that the function remains same after integrating or differentiating it. So the function must be ex


Q3. Magnitude of the vector   is
Answer : Option C
Explaination / Solution:



Q4. The z-Transform of a sequence x[n] is given as X(z) = 2z+4-4/z+3z2. If y[n] is the first difference of x[n], then Y(z) is given by 
Answer : Option A
Explaination / Solution:

y(n) is first difference of x(n) So
g(n)=x(n)-x(n-1)


Q5. If  =  ,then x =
Answer : Option C
Explaination / Solution:



Q6. Let f be a function satisfying f(x + y) = f(x) + f(y) for all x, y then f ‘ (x) =
Answer : Option B
Explaination / Solution:



Q7. Which of the following lines is a normal to the circle 
Answer : Option A
Explaination / Solution:


comparing the above equation with we get center as (1,2)

putting (1,2) in L.H.S of above line ,we get 1+2=3=R.H.S

=> it satisfies center satisfies the equation of line or the line passes through center

and the line passing through the centre is normal.


Q8.

cot  = sin 2  π , n integer) if  equals


Answer : Option B
Explaination / Solution:

sin2θ=cotθ2sinθcosθ=sinθcosθcosθ(2sinθ1sinθ)=0cosθ(12sin2θ)=0cosθ.cos2θ=0cosθ=cosπ20rcos2θ=cosπ2θ=π2,π4[θnπ,nϵZ]
Q9.

If  is divisible by x – k for all n belongs to natural numbers N , then the least positive integral value of k is :


Answer : Option A
Explaination / Solution:

since we have x - 1 as a factor of xn - 1n.

Q10. 8 coins are tossed at a time. The probability of getting 6 heads up is
Answer : Option B
Explaination / Solution:

Total ways of getting 6 heads out of 8 toss of coins is 28.

Total number of outcome is 28 = 256

Therefore probability is