Pijush De

If you don't have any shadows, you're not standing in the light.

Pijush De
EduRev UGC NET
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Discussed Questions

Let T be linear transformation on  into itself such that T(1,0) = (1,2) and T (1, 1) = (0, 2) .Then T(a, b) is equal to
  • a)
    (a, 2b)
  • b)
    (2a, b) 
  • c)
    (a - b, 2a)    
  • d)
    (a - b, 2b)
Correct answer is option 'C'. Can you explain this answer?

Pijush De answered  •  Dec 09, 2021
As {(1,0),(1,1)} form a basis for R^2 so, (a,b) can be written as Linear combination of (1,0) &(1,1).

(a,b) = (a-b)(1,0) + b(1,1)

So, T(a,b) = T(b(1,1) + (a-b)(1,0))
= b T(1,1) + (a-b) T(1,0)
= b (0,2) + (a-b) (1,2)
= (a-b, 2a) [Option C]

Composite number n is
  • a)
    a prime number and n > 1
  • b)
    non-prime number n < 1
  • c)
    non-prime number and n > 1
  • d)
    a prime number and n < 1
Correct answer is option 'C'. Can you explain this answer?

Pijush De answered  •  Feb 27, 2021
Composite numbers can be defined as natural numbers that have more than two factors. In other words, a number which is divisible by a number other than 1 and the number itself, is called a composite number. So composite number never be a prime and also not equal to 1. So the correct answer is option 'C'.

The number of divisiors of 9600 including 1 and 9600 is
  • a)
    60
  • b)
    58
  • c)
    48
  • d)
    46
Correct answer is option 'C'. Can you explain this answer?

Pijush De answered  •  Feb 27, 2021
For this we apply tau function or the number of divisors function, denoted by τ is defined by setting τ(n) equal to the number of positive divisors of n.
Here n = 9600 = 2^7×3×5^2 and τ(9600) = (7+1)×(1+1)×(2+1) = 48 (option C).

The number of positive divisiors of 50,000 is
  • a)
    20
  • b)
    30
  • c)
    40
  • d)
    50
Correct answer is option 'B'. Can you explain this answer?

Pijush De answered  •  Feb 27, 2021
For this we apply tau function or the number of divisors function, denoted by τ is defined by setting τ(n) equal to the number of positive divisors of n.
Here n = 50000 = 5^5×2^4 and τ(50000) = (5+1)×(4+1) = 30 (option B).

The following table defines a cyclic group

its generators are
  • a)
    A,B
  • b)
    D, B
  • c)
    C, D
  • d)
    D, A
Correct answer is option 'D'. Can you explain this answer?

Pijush De answered  •  Feb 27, 2021
From 2nd row & 2nd column of the above table we see that B is the identity element. Now the number of generators of a cyclic group can be found using Euler's phi function. Here φ(4) = φ(2^2) = (2^2) - 2 = 2 i.e. the group has 2 generators. Now C^2 = B = Identity element. So order of C = 2 ≠ 4 ⇒C isn't a generator for a group of order 4 & also B is the identity element. Therefore the two generator... more

The number of generators in cyclic group of order 10 are
  • a)
    3
  • b)
    1
  • c)
    2
  • d)
    4
Correct answer is option 'D'. Can you explain this answer?

Pijush De answered  •  Feb 27, 2021
Use Euler's phi function as follows :
Euler's totient function counts the positive integers up to a given integer n that are relatively prime to n and denoted by Greek letter phi as φ(n). The number of generators of a cyclic group can be found using Euler's phi function.
So here φ(10) = φ(5)×φ(2) [as 5 & 2 are relatively prime]. = (5 -1) × 1 = 4.

Number of elements of the cyclic group of order 6 can be used as generators of the group are
  • a)
    = 3
  • b)
    = 5
  • c)
    = 2
  • d)
    4
Correct answer is option 'C'. Can you explain this answer?

Pijush De answered  •  Feb 27, 2021
Use Euler's phi function as follows :
Euler's totient function counts the positive integers up to a given integer n that are relatively prime to n and denoted by Greek letter phi as φ(n). The number of generators of a cyclic group can be found using Euler's phi function.
So here φ(6) = φ(3)×φ(2) [as 3 & 2 are relatively prime]. = 2.

The number of generators of a cyclic group of order 12 is ________.
    Correct answer is '4'. Can you explain this answer?

    Pijush De answered  •  Feb 27, 2021
    Use Euler's phi function as follows :
    Euler's totient function counts the positive integers up to a given integer n that are relatively prime to n and denoted by Greek letter phi as φ(n). The number of generators of a cyclic group can be found using Euler's phi function.
    So here φ(12) = φ(4)×φ(3) [as 3 & 4 are relatively prime]. = 2 × 2
    = 4.
    Pijush De upvoted   •  Jun 19, 2020

    If f(x) is differentiable on interval l and such that |f'(x)| ≤ a on l, then f(x) is
    • a)
       Continuous but not uniformly continuous on l
    • b)
      Uniformly continuous but not continuous on l
    • c)
      Uniformly continuous but not differentiable on l
    • d)
      Continuous, uniformly continuous and differentiable on l
    Correct answer is option 'A'. Can you explain this answer?

    Chirag Verma answered
    For xy ∈ l, by Lagrange’s mean value theorem
    where x < c < y
    implies f(x)- f(y) = (x - y) f '(c )
    implies |f(x) - f(y) | = x - y || f'(c)|
    for a given  such that |f(x) - f(y)| < ε, x, y ∈ l. Hence f(x) is uniformly continuous on l. We know that every uniformly continuous function is also continuous.

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