Question Number 2649 by Filup last updated on 24/Nov/15
$$\mathrm{Ok}\:\mathrm{guys}.\:\mathrm{We}\:\mathrm{all}\:\mathscr{LOVE}\:\mathrm{mathematics}. \\ $$$$\mathrm{So},\:\mathrm{I}\:\mathrm{have}\:\mathrm{came}\:\mathrm{up}\:\mathrm{with}\:\mathrm{a}\:\mathrm{simple}\:\mathrm{and} \\ $$$$\mathrm{possibly}\:\mathrm{effect}\:\mathrm{way}\:\mathrm{to}\:\mathrm{not}\:\mathrm{only}\:\mathrm{improve} \\ $$$$\mathrm{our}\:\mathrm{abilities}\:\mathrm{as}\:\mathrm{mathematicians},\:\mathrm{but}\:\mathrm{also} \\ $$$$\mathrm{have}\:\mathrm{some}\:\mathrm{fun},\:\mathrm{too}. \\ $$$$ \\ $$$$\mathrm{We}\:\mathrm{should}\:\mathrm{hold}\:\mathrm{a}\:\mathrm{competition}\:\mathrm{every} \\ $$$$\mathrm{now}\:\mathrm{and}\:\mathrm{again}.\:\mathrm{We}\:\mathrm{can},\:\mathrm{for}\:\mathrm{example} \\ $$$$\mathrm{have}\:\mathrm{questions}\:\mathrm{such}\:\mathrm{as}\:\mathrm{the}\:\mathrm{following}: \\ $$$$ \\ $$$$\left(\overset{\rightarrow} {\boldsymbol{{v}}},\:\overset{\rightarrow} {\boldsymbol{{k}}}\right)\in\mathbb{R}^{{n}} ,\:\overset{\rightarrow} {\boldsymbol{{v}}}=\langle{v}_{\mathrm{1}} ,\:…,\:{v}_{{n}} \rangle,\:\overset{\rightarrow} {\boldsymbol{{k}}}=\langle\mathrm{1},\:\mathrm{1},\:…,\:\mathrm{1}\rangle. \\ $$$$\mathrm{Prove}\:\mathrm{that}\:\mathrm{if}\:\boldsymbol{{v}}\bullet\boldsymbol{{k}}=\mathrm{0},\:\boldsymbol{{v}}\:\mathrm{and}\:\boldsymbol{{k}}\:\mathrm{are}\:\mathrm{orthoganal}. \\ $$$$\mathrm{Do}\:\mathrm{so}\:\mathrm{in}\:\mathrm{the}\:\mathrm{most}\:\mathrm{creative}\:\mathrm{way}\left(\mathrm{s}\right)\:\mathrm{or}\:\mathrm{most} \\ $$$$\mathrm{complex}. \\ $$$$ \\ $$$$\mathrm{Let}\:\mathrm{this}\:\mathrm{post}\:\mathrm{be}\:\mathrm{a}\:{trial}\:\mathrm{competition}. \\ $$$$\mathrm{If}\:\mathrm{this}\:\mathrm{goes}\:\mathrm{well},\:\mathrm{we}\:\mathrm{should}\:\mathrm{continue} \\ $$$$\mathrm{doing}\:\mathrm{more}\:\mathrm{in}\:\mathrm{the}\:\mathrm{future}! \\ $$$$ \\ $$$${Good}\:{Luck} \\ $$$$ \\ $$$${Edit}: \\ $$$$\mathrm{Let}\:\mathrm{me}\:\mathrm{know}\:\mathrm{what}\:\mathrm{you}\:\mathrm{all}\:\mathrm{think}! \\ $$
Commented by prakash jain last updated on 24/Nov/15
$$\mathrm{How}\:\mathrm{about}\:\mathrm{we}\:\mathrm{set}\:\mathrm{up}\:\mathrm{a}\:\mathrm{topic}\:\mathrm{at}\:\mathrm{the}\:\mathrm{beginning} \\ $$$$\mathrm{of}\:\mathrm{the}\:\mathrm{month}\:\mathrm{and}\:\mathrm{challenge}\:\mathrm{on}\:\mathrm{that}\:\mathrm{topic} \\ $$$$\mathrm{at}\:\mathrm{the}\:\mathrm{end}\:\mathrm{of}\:\mathrm{the}\:\mathrm{month}. \\ $$$$\mathrm{This}\:\mathrm{way}\:\mathrm{we}\:\mathrm{cover}\:\mathrm{one}\:\mathrm{new}\:\mathrm{topic}\:\mathrm{every}\:\mathrm{month}. \\ $$$$\mathrm{Topic}\:\mathrm{can}\:\mathrm{be}\:\mathrm{for}\:\mathrm{example}\:\mathrm{series}\:\mathrm{convergence}, \\ $$$$\mathrm{etc}. \\ $$$$\mathrm{Everybody}\:\mathrm{can}\:\mathrm{always}\:\mathrm{put}\:\mathrm{question}\:\mathrm{on} \\ $$$$\mathrm{other}\:\mathrm{topic}\:\mathrm{anytime}. \\ $$
Commented by RasheedAhmad last updated on 24/Nov/15
$${Participants}\:{here}\:{are}\:{of}\:{different} \\ $$$${levels}\:{and}\:{also}\:{they}\:{belong}\:{to} \\ $$$${different}\:{areas}\:{of}\:{maths}. \\ $$$${They}\:{can}'{t}\:{be}\:{forced}\:{to}\:{answer} \\ $$$${suggested}\:{question}/{s}.{For}\:{example} \\ $$$${I}\:{am}\:{not}\:{in}\:{position}\:{now}\:{to}\: \\ $$$${answer}\:{your}\:{Q}\:{because}\:{at}\:{the} \\ $$$${instant}\:{I}\:{have}\:{forgotten}\:{Vectors}. \\ $$$${Anyway}\:{I}\:{appreciate}\:{your}\:{passions}. \\ $$
Commented by Filup last updated on 24/Nov/15
$$\mathrm{Thats}\:\mathrm{a}\:\mathrm{good}\:\mathrm{point}!\:{M}\mathrm{aybe}\:\mathrm{we}\:\mathrm{can}\:\mathrm{offer} \\ $$$$\mathrm{different}\:\mathrm{levels}\:\mathrm{of}\:\mathrm{difficulty}\:\mathrm{or}\:\mathrm{something}? \\ $$
Commented by Yozzi last updated on 24/Nov/15
$${I}'{m}\:{no}\:{fan}\:{of}\:{mathematics}\:{competitions} \\ $$$$\left({probably}\:{because}\:{I}'{m}\:{terribly}\:{slow}\:{at}\:{problem}\right. \\ $$$$\left.{solving}\:{in}\:{unknown}\:{areas}\right)\:{but}\:{I}'{ll}\:{try}\:{the}\:{questions}\:{for} \\ $$$${the}\:{benefit}\:{of}\:{improving}\:{my}\:{abilities}. \\ $$$$ \\ $$
Commented by Filup last updated on 24/Nov/15
$$\mathrm{I}{t}\:\mathrm{wouldnt}\:\mathrm{be}\:\mathrm{a}\:\mathrm{race}…\:\mathrm{more}\:\mathrm{of}\:\mathrm{a}\:\mathrm{way}\:\mathrm{of} \\ $$$$\mathrm{finding}\:\mathrm{the}\:\mathrm{most}\:\mathrm{unique}\:\mathrm{answers}? \\ $$
Commented by Yozzi last updated on 24/Nov/15
$${That}\:{seems}\:{more}\:{sensible}: \\ $$$${a}\:{search}\:{for}\:{the}\:{different}\:{solutions} \\ $$$${for}\:{a}\:{given}\:{problem}\:\left({if}\:{there}\:{are}\:{a}\right. \\ $$$$\left.{finite}\:{number}\:{of}\:{distinct}\:{methods}\right). \\ $$
Commented by 123456 last updated on 24/Nov/15
$$\mathrm{nice}. \\ $$
Commented by Yozzi last updated on 24/Nov/15
$${I}\:{like}\:{that}\:{idea}. \\ $$
Commented by 123456 last updated on 01/Dec/15
$$\mathrm{the}\:\mathrm{new}\:\mathrm{topic}\:\mathrm{will}\:\mathrm{be}\:\mathrm{opened}\:\mathrm{on}\:\mathrm{the} \\ $$$$\mathrm{first}\:\mathrm{day}\:\mathrm{of}\:\mathrm{mouth}\:\mathrm{or}\:\mathrm{1}\:\mathrm{mouth} \\ $$$$\mathrm{after}\:\mathrm{the}\:\mathrm{other}? \\ $$
Commented by prakash jain last updated on 09/Dec/15
$$\mathrm{Let}\:\mathrm{us}\:\mathrm{try}\:\mathrm{at}\:\mathrm{the}\:\mathrm{beginning}\:\mathrm{of}\:\mathrm{the}\:\mathrm{month}. \\ $$