phi
Reputation
217
Next privilege 250 Rep.
 Nov 30 awarded Popular Question Jul 2 awarded Curious May 28 awarded Yearling Aug 12 comment Show that if $\lfloor x+a \rfloor$ = $\lfloor x+b \rfloor, \forall x \in \Bbb R$ then $a=b$; is showing that $x+a=x+b$ enough? Not sure if this is correct... Jul 21 comment Showing that $A = \{\tan x \mid x \in (-\frac{\pi}{2}, \frac{\pi}{2})\}$ is not bounded, without calculus. well for every y in R the equation tan x = y has at least a solution in (-pi/2, pi/2), x = arctan y + kpi Jul 21 comment Showing that $A = \{\tan x \mid x \in (-\frac{\pi}{2}, \frac{\pi}{2})\}$ is not bounded, without calculus. Well since tan has codomain R and is surjective Im(tan) must be R, How to show that R is the domain of tan...than i dont know Jul 21 comment Showing that $A = \{\tan x \mid x \in (-\frac{\pi}{2}, \frac{\pi}{2})\}$ is not bounded, without calculus. I guess Calculus was developed to answer this kind of questions Jul 21 comment Showing that $A = \{\tan x \mid x \in (-\frac{\pi}{2}, \frac{\pi}{2})\}$ is not bounded, without calculus. Its six x/cos x Jul 21 asked Showing that $A = \{\tan x \mid x \in (-\frac{\pi}{2}, \frac{\pi}{2})\}$ is not bounded, without calculus. Jul 10 accepted Infimum, supremum of a set problems Jul 10 comment Infimum, supremum of a set problems god it was so simple, didn't even think about this, thanks. Jul 10 comment Infimum, supremum of a set problems yes i do but i am not supposed to use it on this problem, it would be too easy, i am looking for a different solution... Jul 10 comment Infimum, supremum of a set problems i tried like this, -1 < x < 1 and 0 <= x^2 < 1 adding them up gives -1 < x^2 + x < 2, so inf A = -1 not sure if it is correct Jul 10 comment Infimum, supremum of a set problems Its very annoying when you cant even rely on the solutions in the book, good this website exists! Jul 10 asked Infimum, supremum of a set problems May 23 comment Limit of sequence, sequence is formed by the root of an equation. But i know that one is right. Just i wasn't sure about this part. May 23 comment Limit of sequence, sequence is formed by the root of an equation. Well i proved it using one of the consequences of Rolle's theorem May 23 comment Limit of sequence, sequence is formed by the root of an equation. because $X_n \in (1, \infty) \ \forall n \ge 2$ and $n \to \infty$ May 23 asked Limit of sequence, sequence is formed by the root of an equation. May 19 accepted How many functions $f:\{1,2,3,4\}→\{1,2,3,4\}$ satisfy $f(1)=f(4)$?