Question

Trigonometri- 1C caranya gimana ya? Trims

Answer 1

Sec α - tan α .sin α = cos α
sec α - sin α/cos α .sin α = ruas kanan
sec α - sin^2α/cos α = ruas kanan
sec α - secα sin^2α = ruas kanan
sec α(1- sin^2α) = ruas kanan
sec α cos^2α = ruas kanan
cos α =ruas kanan
ruas kiri = ruas kanan (terbukti)