Question Number 186486 by a.lgnaoui last updated on 05/Feb/23
$${Question}\:{propose}\:{par} \\ $$$${Migma} \\ $$$$−−−−−−−−−−− \\ $$$${calcul}\:{de}\:{X} \\ $$$$ \\ $$$$\bigtriangleup{ABC}\:\:\:\:\:\:\measuredangle{ACB}=\mathrm{40}^{°} \\ $$$$\mathrm{AB}^{\mathrm{2}} =\mathrm{AC}^{\mathrm{2}} +\mathrm{BC}^{\mathrm{2}} −\mathrm{2AC}×\mathrm{BCcos}\:\mathrm{40}\:\:\:\: \\ $$$$\mathrm{AC}=\mathrm{15}\:\:;\:\:\:\:\mathrm{AB}=\mathrm{X}+\mathrm{4}\:;\:\:\:\mathrm{BC}=\mathrm{10} \\ $$$$\left(\mathrm{X}+\mathrm{4}\right)^{\mathrm{2}} =\mathrm{15}^{\mathrm{2}} +\mathrm{10}^{\mathrm{2}} −\mathrm{300}×\mathrm{cos}\:\mathrm{40} \\ $$$$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:=\mathrm{325}−\mathrm{229},\mathrm{81334} \\ $$$$\left({X}+\mathrm{4}\right)^{\mathrm{2}} =\mathrm{95},\mathrm{18666706} \\ $$$${posons}\:\:\:{Z}={X}+\mathrm{4} \\ $$$$\:\:\:{Z}^{\mathrm{2}} =\mathrm{9},\mathrm{756}^{\mathrm{2}} \:\:\:\:\Rightarrow\mathrm{X}+\mathrm{4}=\mathrm{9},\mathrm{756} \\ $$$$ \\ $$$$\:\:\:\:\:\:\:\:\:\:{X}=\mathrm{5},\mathrm{756} \\ $$$$ \\ $$
Commented by a.lgnaoui last updated on 05/Feb/23
Commented by mr W last updated on 05/Feb/23
$${it}'{s}\:{wrong}\:{and}\:{non}−{sense}\:{again}. \\ $$$${it}'{s}\:{adventurous}\:{how}\:{you}\:{treat} \\ $$$${mathematics}!\:{sometimes}\:{you}\:{just} \\ $$$${measure}\:{a}\:{figure}\:{and}\:{find}\:{that}\:{a}\:{triangle} \\ $$$${looks}\:{like}\:{equilateral}\:{and}\:{then}\:{you} \\ $$$${set}\:{it}\:{as}\:{equilateral}\:{and}\:{solve}\:{the} \\ $$$${question}.\:{in}\:{current}\:{case}\:{an}\:{angle}\:{is}\: \\ $$$${just}\:{marked}\:{as}\:\mathrm{4}\alpha,\:{and}\:{you}\:{simply}\:{set}\: \\ $$$${it}\:{as}\:\mathrm{40}°\:{and}\:{solve}\:{the}\:{question},\: \\ $$$${without}\:{taking}\:{other}\:{information}\: \\ $$$${and}\:{conditions}\:{into}\:{consideration}.\: \\ $$$${i}'{m}\:{sorry}\:{to}\:{say}\:{that}\:{you}\:{treat}\: \\ $$$${mathematics}\:{basically}\:{not}\:{as}\:{an}\: \\ $$$${exact}\:{and}\:{strict}\:{thing}\:{and}\:{thus}\:{in}\: \\ $$$${many}\:{cases}\:{your}\:\:{so}−{called}\:{solutions}\: \\ $$$${are}\:{just}\:{non}−{sense},\:{which}\:{i}\:{don}'{t} \\ $$$${think}\:{you}\:{need}\:{to}\:{share},\:{because} \\ $$$${such}\:{solutions}\:{will}\:{help}\:{nobody}\:{else}\: \\ $$$${in}\:{any}\:{way}. \\ $$$${i}\:{don}'{t}\:{want}\:{to}\:{disencourage}\:{you},\: \\ $$$${i}\:{just}\:{think}\:{you}\:{should}\:{generally} \\ $$$${consider}\:{to}\:{take}\:{mathematics}\:{as}\:{a} \\ $$$${serious},\:{exact}\:{and}\:{strict}\:{matter}. \\ $$
Commented by a.lgnaoui last updated on 05/Feb/23
$${there}\:{is}\:{many}\:{way}\:{to}\:{have}\:{a}\:{solutiin} \\ $$$${but}\:{and}\:{my}\:{methode}\:{is} \\ $$$${correct}\:{perhapse}\:{you}\:{prefere} \\ $$$${your}\:{methode}\:{but}\:{do}\:{not} \\ $$$${say}\:{that}\:{mine}\:{is}\:{wrong} \\ $$$${I}\:{have}\:{trying}\:{authere}\:{similar} \\ $$$${methode}\:\:{and}\:{I}\:{had}\:{founding}\:{the}\:{same}\:{resultat}\:{but}\:{the}\:{radical} \\ $$$${complexe}\:{the}\:{resultat} \\ $$$${so}\:{I}\:{had}\:{prefer}\:{this}\: \\ $$$${all}\:{can}\:{resolve}\:{with}\:{his} \\ $$$${methode}\:\left({raisonnable}\:\right) \\ $$$${with}\:{tools}\:{and}\:{lows}\left({lois}\right){mathematics} \\ $$$${and}\:{Excuse}\:{me}\:{and}\:{all}\: \\ $$$${autere}\:{for}\:{the}\:{probleme}\:{of} \\ $$$${language}\:{english}\:{because} \\ $$$${I}\:{had}\:{studing}\:{with}\:{langage} \\ $$$${Arabic}\:{and}\:{frensh}\:\:{but}\:{this} \\ $$$${was}\:{not}\:{a}\:{principal}\:{probleme} \\ $$$${I}\:{comment}\:{some}\:{questions} \\ $$$${posting}\:{by}\:\:{frends}\:\:{and}\: \\ $$$${I}\:{add}\:\left({like}\right){when}\:{I}\:{receive} \\ $$$${the}\:{answer}\: \\ $$$${If}\:{any}\:{answers}\:{are}\:{not}\: \\ $$$${exact}\left({correct}\right)\:{the}\:<{intervenants}> \\ $$$${can}\:{samply}\:\:{give}\:{her}\:{ideas}\:{to}\:{explain} \\ $$$${why}\:{the}\:{answer}\:{is}\:{thrue}\:{or}\:{not} \\ $$$${I}\:{practisse}\:{mathematic} \\ $$$${because}\:{I}\:{like}\:{it}\:{and}\:{not}\: \\ $$$${simply}\:{to}\:{look}\:{the}\:{answers}. \\ $$$$−{Ahmed}\:{LAGNAOUI}− \\ $$$${Membre}\:{in}\:{forum}: \\ $$$${Editeur}\:{Mathematique}. \\ $$$$−−−−−−−−−{End}. \\ $$
Commented by mr W last updated on 05/Feb/23
$${since}\:{the}\:{forum}\:{is}\:{a}\:{public}\:{place}, \\ $$$${it}\:{is}\:{normal}\:{and}\:{even}\:{expected}\:{that} \\ $$$${one}'{s}\:{posts}\:\left({solutions}\:{or}\:{comments}\right) \\ $$$${are}\:{commented}\:{by}\:{others}.\:{i}'{m}\:{not} \\ $$$${talking}\:{about}\:{if}\:{a}\:{method}\:{is}\:{good} \\ $$$${or}\:{bad},\:{in}\:{current}\:{case}\:{it}\:{is}\:{not} \\ $$$${a}\:{method}\:{at}\:{all},\:{but}\:{just}\:{non}−{sense}, \\ $$$${that}\:{an}\:{angle},\:{which}\:{is}\:{marked}\:{as}\: \\ $$$$\mathrm{4}\alpha\:{simply}\:{taken}\:{as}\:{an}\:{angle}\:{of}\:\mathrm{40}°. \\ $$$${since}\:{this}\:{is}\:{presented}\:{in}\:{forum}\:{as} \\ $$$${solution},\:{i}\:{think}\:{it}\:{is}\:{allowed}\:{for}\:{me} \\ $$$${to}\:{say}\:{it}\:{is}\:{wrong}.\:{when}\:{this}\:{is}\: \\ $$$${inappropriate}\:{for}\:{you},\:{i}\:{say}\:{i}'{m}\:{sorry} \\ $$$${and}\:{won}'{t}\:{comment}\:{any}\:{more}\:{in}\: \\ $$$${future}. \\ $$
Commented by Frix last updated on 05/Feb/23
$$\mathrm{There}\:\mathrm{are}\:\mathrm{many}\:\mathrm{ways}\:\mathrm{to}\:\mathrm{find}\:\mathrm{a}\:\mathrm{solution}\:\mathrm{but} \\ $$$$\mathrm{most}\:\mathrm{of}\:\mathrm{the}\:\mathrm{time}\:\mathrm{there}\:\mathrm{is}\:\mathrm{only}\:\mathrm{one}\:\mathrm{solution}. \\ $$$$\mathrm{If}\:\mathrm{your}\:\mathrm{way}\:\mathrm{doesn}'\mathrm{t}\:\mathrm{lead}\:\mathrm{to}\:\mathrm{this}\:\mathrm{solution} \\ $$$$\Rightarrow\:\mathrm{your}\:\mathrm{way}\:\mathrm{is}\:\mathrm{wrong}. \\ $$$$\mathrm{But}\:\mathrm{there}\:\mathrm{are}\:\mathrm{also}\:\mathrm{rules}.\:\mathrm{If}\:\mathrm{you}\:\mathrm{don}'\mathrm{t}\:\mathrm{obey} \\ $$$$\mathrm{the}\:\mathrm{rules}\:\mathrm{of}\:\mathrm{a}\:\mathrm{certain}\:\mathrm{game},\:\mathrm{you}'\mathrm{re}\:\mathrm{playing} \\ $$$$\mathrm{a}\:\mathrm{different}\:\mathrm{game}\:\mathrm{instead}.\:\mathrm{If}\:\mathrm{the}\:\mathrm{king}\:\mathrm{on} \\ $$$$\mathrm{your}\:\mathrm{chessboard}\:\mathrm{moves}\:\mathrm{like}\:\mathrm{a}\:\mathrm{knight}\:\mathrm{you}'\mathrm{re} \\ $$$$\mathrm{not}\:\mathrm{playing}\:\mathrm{chess}. \\ $$$$\mathrm{You}\:\mathrm{don}'\mathrm{t}\:\mathrm{follow}\:\mathrm{the}\:\mathrm{rules}\:\mathrm{of}\:\mathrm{mathematics} \\ $$$$\mathrm{very}\:\mathrm{often}\:\Rightarrow\:\mathrm{you}'\mathrm{re}\:\mathrm{not}\:\mathrm{doing}\:\mathrm{mathematics}. \\ $$
Commented by a.lgnaoui last updated on 05/Feb/23
$${with}\:\mathrm{4}\alpha\:{authere}\:{solution} \\ $$$${Now}\:{I}\:{understand}\:{where}\:{is}\:{error} \\ $$$$ \\ $$