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Apr
23
reviewed Leave Closed Who are the big names in Mathematics nowadays?
Apr
22
reviewed Reviewed lagrange's theorem exercise help
Apr
21
asked calculus of variations with free endpoint
Apr
21
reviewed Approve Continued Fraction
Apr
15
reviewed Looks OK Find the number of ways to form 15 teams out of 15 men and 15 women.
Apr
14
reviewed Reviewed Find a one-to-one correspondence (i.e, a bijection)
Apr
14
reviewed Looks OK Complicated inequality, how to prove?
Apr
14
reviewed Looks OK Online service for completing the square
Apr
12
comment Determine the coefficient of polynomial det(I + xA)
Yes. To get $x^2$, you need $x^{n-2}$ copies of $x$ to cancel. This means you will get products of 2 eigenvalues and $n-2$ 1s.
Apr
11
answered ${x^*}Bx \in R$ for all $x \in {C^n}$. Why $B = {B^*}$.
Apr
10
reviewed Looks OK CW -complex structure of boundary of a manifold
Apr
9
reviewed Close Can find the determinant of a matrix A of size $n$ in terms of the traces of $A^m$
Apr
9
reviewed Leave Open Solve for $x$ in the congruence $2x \equiv 7\pmod{17}$
Apr
9
reviewed Close Showing that $\{x\mid f(x)\leq g(x)\}$ is closed.
Apr
9
reviewed Leave Open Are there any irrational numbers that have a difference of a rational number?
Apr
9
reviewed Leave Open The unique loop $L$ (quasigroup with unit) of order $5$ satisfying $x^2 = 1$ for all $x \in L$
Apr
9
reviewed Looks OK Solve for $x$ in the congruence $2x \equiv 7\pmod{17}$
Apr
9
reviewed Looks OK Solve for $x$ in the congruence $2x \equiv 7\pmod{17}$
Apr
9
comment Solve for $x$ in the congruence $2x \equiv 7\pmod{17}$
Although that doesn't explain why you can "obviously" cancel 2s from both sides.
Apr
9
reviewed Reopen A sequence for which there is $k$ such that for each $\epsilon >0$ we have that $|x_n -l | < \epsilon$ for all $n \geq k$