Leej twg nrhiav tau txoj cai ntawm sines thiab cosines?
Leej twg nrhiav tau txoj cai ntawm sines thiab cosines?

Video: Leej twg nrhiav tau txoj cai ntawm sines thiab cosines?

Video: Leej twg nrhiav tau txoj cai ntawm sines thiab cosines?
Video: 6 Nqi Lus Qhia Kev Ua neej ( leej twg mloog lub neej yuav zoo tuaj) 2024, Kaum ib hlis
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Euclid's Elements pave the way for the nrhiav pom ntawm txoj cai ntawm cosines . Nyob rau hauv lub xyoo pua 15th, Jamshīdal-Kāshī, ib tug Persian lej thiab astronomer, tau muab thawj cov lus qhia meej ntawm lub txoj cai ntawm cosines nyob rau hauv ib daim ntawv haum rau triangulation.

Ib yam li ntawd, nws raug nug, leej twg nrhiav tau txoj cai ntawm kev txhaum?

Ib nrab chords, los yog sines , tau qhia los ntawm Hindu mathematician Aryabhata nyob ib ncig ntawm 500. Lub spherical law ofsines yog thawj zaug nthuav tawm nyob rau sab hnub poob los ntawm Johann Muller, tseem hu ua Regiomontus, hauv nws De Triangulis Omnimodis hauv 1464. Qhov no yog thawj phau ntawv mob siab rau tag nrho rau trigonometry (ib lo lus tsis yog tom qab ntawd).

Tom qab ntawd, lo lus nug yog, txoj cai ntawm sines thiab cosines yog dab tsi? Cov Txoj Cai ntawm Sines thiab Cosines . Cov Law ofSines tsim kom muaj kev sib raug zoo ntawm cov ces kaum thiab qhov ntev ntawm ΔABC: Qhov no yog qhov tshwm sim ntawm qhov tseeb tias cosine , tsis zoo li sib , hloov nws cov kos npe nyob rau hauv thaj tsam 0 ° - 180 ° ntawm cov ces kaum siv tau ntawm daim duab peb sab.

Ib yam li ntawd, nws yog nug, leej twg nrhiav tau sine thiab cosine?

Thawj lub rooj paub ntawm chords tau tsim los ntawm Greek lej Hipparchus hauv 140 BC. Txawm hais tias cov txheej txheem tseem tsis tau muaj sia nyob, nws tau lees tias kaum ob phau ntawv ntawm cov lus chords tau sau los ntawm Hipparchus. Qhov no ua rau Hipparchus tus tsim ntawm trigonometry.

Dab tsi yog qhov sib npaug rau txoj cai ntawm sines?

Yooj yim, nws hais tias qhov sib piv ntawm qhov ntev ntawm ib sab ntawm daim duab peb sab rau qhov sib ntawm lub kaum sab nraud ntawm sab yog tib yam rau txhua sab thiab cov kaum hauv ib daim duab peb sab muab. Hauv ΔABC yog daim duab peb sab oblique nrog sab a, b thiab c, thenasinA = bsinB = csinC.

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