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stewbasic
  • Member for 7 years, 7 months
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59 votes

Find three non-constant, pairwise unequal functions $f,g,h:\mathbb R\to \mathbb R$...

36 votes
Accepted

Solve 6th degree polynomial: $(x^2 - 3x - 4)(x^2 - 5x + 6)(x^2 + 2x) + 30$

19 votes
Accepted

Solutions to $f'=f$ over the rationals

16 votes

If $(A-B)^2=AB$, prove that $\det(AB-BA)=0$.

14 votes

What is the fewest number of squares required to cover a $11\times13\text{ cm}$ rectangle without overlap?

12 votes
Accepted

Functional Equation $f(x+f(x))=x+f(x)$

10 votes
Accepted

Does this operation exist? What's its name?

10 votes

Find all functions $f\colon \mathbb{R}^* \to \mathbb{R}^* $ satisfying $f(xyz)=f(xy+yz+xz)\big(f(x)+f(y)+f(z)\big)$ when $xy+yz+xz\ne 0$

7 votes

How to show the Jungle River Metric is Complete

6 votes
Accepted

Hard inequality with cos() and sin()

6 votes
Accepted

Does the series $\sum_{n=1}^{\infty}\frac{\sin(\cos(n))}{n}$ converge?

6 votes
Accepted

Is $x^5 + x^3 + 1$ irreducible in $\mathbb{F}_{32}$ and $\mathbb{F}_8$?

6 votes
Accepted

Find the function $f(x)$ if $f(x+2f(y))=f(x)+y+f(y)$

6 votes
Accepted

What is the set of triangular numbers mod $n$?

6 votes
Accepted

how to prove that $I \cong \mathrm{Hom}_R(I,R)$

5 votes
Accepted

Irreducibility of a polynomial with no roots over $K$, $\mbox{char} K= p$

5 votes
Accepted

If GCD $(a_1,\ldots, a_n)=1$ then there's a matrix in $SL_n(\mathbb{Z})$ with first row $(a_1,\ldots, a_n)$

5 votes
Accepted

Prove that $\Bbb{R}[\cos(\theta),\sin(\theta)]\cong\Bbb{R}[x,y]/(1-x^2-y^2)$

5 votes

Can the boy escape the teacher for a regular $n$-gon?

5 votes

True or false : $\gcd(a_m, a_n) = a_{\gcd(m, n)}$?

5 votes

How does calculus without Euler's number (e) look?

4 votes

Must a multiplicative bijection on a ring $R \rightarrow R'$ with all elements nilpotent or units be an isomorphism?

4 votes

Restricted Nim : Similarities between problem sets

4 votes
Accepted

Stabilizer of a Group Action

4 votes
Accepted

Normal Group and Conjugacy Class

4 votes
Accepted

$\frac{xy}{z+1}+\frac{yz}{x+1}+\frac{zx}{y+1}$ is an integer

4 votes
Accepted

The ideal of the image of homogeneous polynomials

4 votes
Accepted

In a coxeter group, if $s_1\dots s_n=t_1\dots t_n$ then $t_1s_1\cdots s_r=s_1\cdots s_{r+1}$?

4 votes

How can I turn $(a_n-a_{n-1})^2-4a_na_{n-1}-8=0$ into $a_n=\frac12\left((1+\sqrt2)^{2n+1}+(1-\sqrt2)^{2n+1}\right)$?

4 votes
Accepted

If $A$ and $B$ don't contain rays, can $Conv(A\cup B)$ contain a ray?

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