Kev piav qhia: Yuav kom nrhiav tau qhov nce thiab txo qis, peb yuav tsum nrhiav qhov twg peb thawj qhov txiaj ntsig ntau dua lossis tsawg dua xoom. Yog tias peb thawj qhov txiaj ntsig zoo, peb qhov kev ua haujlwm qub yog nce ntxiv thiab yog tias g'(x) tsis zoo, g(x) poob qis.
Koj pom qhov ncua sij hawm nce thiab txo li cas?
Peb tuaj yeem qhia tau li cas yog tias muaj nuj nqi nce lossis txo qis?
- Yog f′(x)>0 ntawm lub sijhawm qhib, ces f nce ntxiv rau lub sijhawm.
- Yog f′(x)<0 ntawm lub sijhawm qhib, ces f yuav txo qis ntawm lub sijhawm.
Koj pom qhov txo qis ntawm kev ua haujlwm li cas?
Kev piav qhia: txhawm rau pom thaum muaj nuj nqi txo qis, koj yuav tsum ua ntej coj tus derivative, tom qab ntawd muab nws sib npaug rau 0, thiab tom qab ntawd nrhiav ntawm qhov twg xoom qhov tseem ceeb qhov kev ua tsis zooTam sim no sim ntsuas qhov tseem ceeb ntawm txhua sab ntawm cov no kom pom thaum lub luag haujlwm tsis zoo, thiab yog li txo qis.
Dab tsi yog qhov nce ntxiv ntawm daim duab?
Daim duab muaj nqes zoo. Los ntawm kev txhais: Ib qho kev ua haujlwm nruj zuj zus ntawm lub sijhawm, if thaum x1 < x2, ces f (x 1) < f (x2) Yog hais tias lub luag haujlwm tseem ceeb cuam tshuam rau koj, lub ntsiab lus no tuaj yeem xav tias yog hais x 1 < x2 implies y1 < y2 Raws li tus x yuav loj dua, tus y tau loj dua.
Puas nce thiab txo qis ib ntus muaj cov hlua?
Ib txwm siv kab lus, tsis yog lub cim, nrog qhov tsis muaj tseeb lossis qhov tsis zoo. Koj kuj siv kab lus rau 2 vim tias ntawm 2, daim duab tsis nce lossis txo- nws yog tiaj tus. Txhawm rau nrhiav cov ntu uas daim duab tsis zoo lossis qhov zoo, saib x-intercepts (tseem hu ua zeros).
