Nov
26
comment Can you construct a field with 6 elements?
Why must $\langle F, +\rangle$ be a cyclic group?
Nov
26
revised What is the coefficient of the $x^3$ term in the expansion of $(x^2+x-5)^7$ (See details)?
correction of the calculation error
Nov
25
suggested suggested edit on What is the coefficient of the $x^3$ term in the expansion of $(x^2+x-5)^7$ (See details)?
Nov
24
comment Find $x$ such that $x+x^2+x^3=x^9-x^7$
$x^9-x^7-x^3-x^2-x=(x^3-x-1)(x^5+x^2+1)x$
Nov
24
comment Does L'Hôpital's work the other way?
-1 The question is not formulated well. L'Hôpital's rule does not say that this two limites are equal. It says they are equal if some preconditions are fulfilled. Also the limes of the undefinite integrals does not make sense.
Nov
23
comment Solving $(z+1)^5 = z^5$
Why follows $$ \pars{1 + {1 \over z_{n}}}^{5} = \expo{2n\pi\ic}\,,\qquad n = 1, 2, 3, 4 $$ from $$ \pars{1 + {1 \over z}}^{5} = 1 $$
Nov
21
comment Can any one tell me the books for power series?
A book is Abramuwitz & Stegun: Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables You can use WolframAlpha which is documented here. Look up wikipedia for square root. Note the comment of @André Nicolas
Nov
19
awarded  Citizen Patrol
Nov
16
comment Is $ n^2-14n+24 $ a prime number?
-1 because it is incomplete
Nov
15
revised Showing the polynomial $x^4 + x^3 + 4x + 1$ is irreducible in $\mathbb{Q[x]}$.
some errors
Nov
15
answered Showing the polynomial $x^4 + x^3 + 4x + 1$ is irreducible in $\mathbb{Q[x]}$.
Nov
14
comment which is larger number? $\sqrt{7}-\sqrt{6}$ or $\sqrt{6}-\sqrt{5}$
+1 for $\stackrel{?}{\lt\gt}$
Nov
14
revised which is larger number? $\sqrt{7}-\sqrt{6}$ or $\sqrt{6}-\sqrt{5}$
simpliying the notation
Nov
14
revised which is larger number? $\sqrt{7}-\sqrt{6}$ or $\sqrt{6}-\sqrt{5}$
deleted 69 characters in body
Nov
14
revised which is larger number? $\sqrt{7}-\sqrt{6}$ or $\sqrt{6}-\sqrt{5}$
adding another proof
Nov
13
revised The largest value of $f(n) $
removing *
Nov
12
answered The largest value of $f(n) $
Nov
12
answered Which is larger? $20!$ or $2^{40}$?
Nov
12
answered which is larger number? $\sqrt{7}-\sqrt{6}$ or $\sqrt{6}-\sqrt{5}$
Nov
12
suggested suggested edit on solution of $y^2 - x = 15$ and $x^2 -xy = 2009$