Question

Tentang trigonometri tolong jawabkan no 4 pake cara ya yg serius!

Answer 1

Tanβ= CB/BD
BD=CB/tanβ.......... pers.1
tanα=CB/AB    ↔ AB = AD + BD = 1 + BD
tanα=CB/(1+BD)
CB=(1+BD)tanα  ↔ substitusikan CB ke pers. 1
BD=(1+BD)tanα/tanβ
BD.tanβ=tanα+BDtanα
BDtanβ - BDtanα = tanα
BD(tanα - tanβ) = tanα
BD = tanα / (tanα - tanβ)........(terbukti)