tolong bantu no 9 dan 10
Matematika
Linojunko250900
Pertanyaan
tolong bantu no 9 dan 10
1 Jawaban
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1. Jawaban whongaliem
9) a) cos x .cosec x . tan x = cos x . 1/sin x . sin x / cos x
= 1
b) cos x . cot x + sin x = cos x . cos x /sin x + sin x
= cos² x / sin x + sin x
= (cos² x + sin² x) / sin x
= 1/sin x = cosec x
c) sin x / (1 + cos α) + sin α / (1 - cos α)
= {sin α (1 - cos α) + sin α (1 + cos α)} / (1 - cos α)(1 + cos α)
= sin α (1 - cos α + 1 + cos α) / (1 - cos² α)
= sin α (2) / (1 - cos² α)
= 2.sin α / sin² α
= 2/sin α
d) (sin α + cos α)² + (sin α - cos α)²
= sin² α + 2.sin α .cos α + cos² α + sin² α - 2.sin α .cos α + cos² α
= sin² α + cos² α + sin² α + cos² α
= 1 + 1
= 2
e) (cosec α - cot α) x (1 + cos α) = cosec α + cot α - cot α - cot α . cos α
= 1/sin + (cos α / sin α) .cos α
= (1 - cos² α) / sin α
= sin² α / sin α
= sin α
10) nampaknya ada data yang kurang ...