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KON3
  • Member for 11 years, 8 months
  • Last seen more than a week ago
10 votes
2 answers
527 views

How to find $f$ and $g$ if $f\circ g$ and $g\circ f$ are given?

10 votes
2 answers
259 views

Sum of $1+\frac{1}{2}+\frac{1\cdot2}{2\cdot5}+\frac{1\cdot 2\cdot 3}{2\cdot 5\cdot 8}+\cdots$

7 votes
3 answers
529 views

To find the limit of $\frac{1}{\sin n}+\frac{1}{\cos n}$

6 votes
2 answers
544 views

How to evaluate the sum [duplicate]

6 votes
0 answers
149 views

What is number of group homomorphisms from $D_{12}$ to $D_{18}$?

6 votes
1 answer
2k views

What is the abelianization of the dihedral group?

5 votes
1 answer
292 views

How to show $\frac{\mathbb{Z}_m\times \mathbb{Z}_n}{\langle (a,b)\rangle}\simeq \mathbb{Z}_{\frac mc}\times \mathbb{Z}_{\frac nd}$?

5 votes
3 answers
1k views

Show that every group of order 15 is cyclic using class equation.

5 votes
3 answers
213 views

what is the sum of square of all elements in $U(n)$?

5 votes
3 answers
245 views

How to get determinant of $A$ in terms of tr$(A^k)$?

5 votes
3 answers
353 views

Finding out $S:=1+\frac12-\frac13-\frac14+\frac15+\frac16-\frac17-\frac18+\cdots$

4 votes
2 answers
269 views

Is my proof that $\frac{\pi}{4}=\sum\limits_{n\geq 0}(-1)^n \frac{1}{2n+1}$ correct?

4 votes
2 answers
116 views

How to solve $\int \frac{\tan^{-1}x}{(1+x)^2}dx$?

4 votes
2 answers
2k views

Is Hom$(G_1, G_2)$ a group?

4 votes
0 answers
84 views

How to find the greatest value of $(3x/2)^2(5y/4)^4$ if $4x+3y=1$ holds?

4 votes
3 answers
271 views

Prove that $20!+23$ is a composite number

4 votes
2 answers
304 views

Is $\operatorname{rank}(AQB)=\operatorname{rank}(AB)$ if $Q$ is non-singular?

4 votes
1 answer
108 views

If two finite Abelian groups posses equal number of elements of some particular order, then justify they are isomorphic.

3 votes
0 answers
264 views

What can we say about $D_{2n}$ and $D_n$ if $n$ is even?

3 votes
1 answer
171 views

How to show that $\varphi(m_1)=\varphi(m_2)$ gives $m_1=m_2$?

3 votes
1 answer
358 views

How to show the convergence or divergence of a series of arbitrary terms?

3 votes
2 answers
118 views

Is $Log(i^{1/3})=\frac{1}{3}Log(i)$?

3 votes
1 answer
51 views

Can we write $2^\alpha$ as sum of smaller 2-powers when $\alpha\geqslant 5$ is a positive integer?

3 votes
2 answers
149 views

The value of $\sum\limits_{n=1}^\infty \frac{1}{n^3}$ [closed]

3 votes
0 answers
148 views

Find the differential equation of $\sqrt{1-x^2}+\sqrt{1-y^2}=c(x-y)$. [closed]

3 votes
0 answers
1k views

Find the isomorphism class of subgroup of order 16 in $U(105)$

3 votes
2 answers
2k views

What is the determinant value of $J-I$ if $I$ is identity matrix and $J=(1)_{101\times 101}$? [duplicate]

3 votes
0 answers
80 views

For what values of $x$ will $ax^2+b$ be perfect squares?

3 votes
2 answers
44 views

WHat is the inner steps here?

3 votes
0 answers
141 views

The Fifteen Puzzle and $S_n$ [duplicate]

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