| E |
| C |
| b |
| a |
| D |
| A |
| B |
| c |
1. a2 = b2 + c2 – 2bc cos α
bukti:
sinα =
cos α =
lihat BCD
a2 = CD2 + BC2
a2 = (b sinα)2 + (c – AD)2
a2 = (b sinα)2 + (c - b cos α)2
a2 = b2sin2 α + c2 – 2bc cos α + b2 cos2 α
a2 = b2(sin2 α + cos2 α) + c2 - 2bc cos α
a2 = b2 + c2 – 2bc cos α
2. b2 = a2 + c2 - 2ac cos β
bukti:
Sin β =
Cos β =
ACD
b2 = CD2 + AD2
b2 = (a Sinβ)2 + (c- BD)2
b2 = (a Sinβ)2 + (c - a Cos β)2
b2 = a2 sin2β + c2 – 2ac Cos β + a2 cos2 β
b2 = a2(sin2β + Cos β) + c2 - ac Cos β
b2 = a2 + c2 - 2ac cos β
3. c2 = a2 + b2 – 2ab cos γ
Sin γ =
Cos γ =
c2 = AE2 + BE2
c2 = (b Sin γ)2 + (a – CE)2
c2 = (b Sin γ)2 + (a - b Cos γ)2
c2 = b2 Sin2 γ + a2 – 2ab Cos γ + b2 Cos2 γ
c2 = b2 (sin2 γ + Cos2 γ) + a2 - 2ab Cos γ
c2 = a2 + b2 – 2ab cos γ
aturan tangen
ACD dan BCD
Sin α =
Sin β =
Description: jawaban tugas trigonometri
Rating: 4.5
Reviewer: Pak Sam
ItemReviewed: jawaban tugas trigonometri
Posted by:Mbah Qopet
Admin Pembelajar Updated at: 09.17
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