Tus nqi ntawm kev txhaum 120 yog dab tsi?
Tus nqi ntawm kev txhaum 120 yog dab tsi?

Video: Tus nqi ntawm kev txhaum 120 yog dab tsi?

Video: Tus nqi ntawm kev txhaum 120 yog dab tsi?
Video: Nkauj Tawm Tshiab 2020- yug lo yog ib pab ntxhai -Duab Ntxoo Yaj 2024, Kaum ib hlis
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Sin120 tus nqi yog √3/2. Rau nws yuav muab faib ua kev txhaum (90+x) uas nyob rau hauv lub thib ob quadrant qhov twg kev txhaum tus nqi yeej ib txwm zoo ces nws ua cosx. Yog li cov lus teb rau lo lus nug yog √3/2. Peb tuaj yeem ua nrog ob txoj kev Kev txhaum (90+x) as Kev txhaum (180-x).

Raws li qhov tseeb, tus nqi ntawm kev txhaum 120 degree yog dab tsi?

Raws li peb txhua tus paub cov sine nqi ntawm qee lub ces kaum xws li: 30, 45, 60, 90, 180. qib nws yog vim 120 =(✓3)/2. Muaj txoj cai ntiv tes xoo yooj yim rau qhov no. kev txhaum (90 + x) = + cos x (vim kev txhaum x yog qhov zoo hauv qhov thib ob quadrant.)

Kuj Paub, qhov degree twg yog kev txhaum? kev txhaum 30° thiab kev txhaum 60 °: Ib daim duab peb sab sib npaug muaj txhua lub kaum sab xis ntsuas 60 qib thiab tag nrho peb sab yog sib npaug. Txhawm rau kom yooj yim, peb xaiv txhua sab kom ntev 2. Thaum koj txiav lub kaum sab xis, koj tau txais 30 qib thiab sab opposite yog 1/2 ntawm 2, uas muab rau koj 1.

Xav txog qhov no, qhov tseeb ntawm kev txhaum 240 yog dab tsi?

kev txhaum ( 240 ) = kev txhaum (60 + 180) = - kev txhaum 60.

Cos 180 minus theta yog dab tsi?

Trigonometric ratios ntawm 180 degree minus theta yog ib qho ntawm cov ceg ntawm ASTC cov qauv hauv trigonometry. Trigonometric ratios ntawm 180 degree minus theta muab hauv qab no. txhaum ( 180 ° - θ) = sin θ cos ( 180 ° - θ) = - cos θ tan ( 180 ° - θ) = - tan θ

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