subebe
2. (sec a. csc a - cot a) (sin a - csc a) = - cos a (1/cos a. 1/sin a- cos a/ sin a) (sin a- 1/sin a) = -cos a ((1/ cos a sin a)- cos²a/sin a cos a) (sin a - 1/sin a) = - cos a (sin² a / cos a sin a) (sin a- 1/sin a) = - cos a (sin a/ cos a) (sin a- 1/sin a) = - cos a sin² a/ cos a - 1 / cos a= - cos a - (1 - sin²a) / cos a = - cos a - cos ² a / cos a = - cos a - cos a = - cos a (terbukti
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Takamori37
Mengingat beberapa identitas berupa: sin(90-a) = cos a Dan, sin²a + cos²a = 1 Maka,
Nomor 1. (Sedikit terjadi kesalahan pada soal sepertinya)
(1/cos a. 1/sin a- cos a/ sin a) (sin a- 1/sin a) = -cos a
((1/ cos a sin a)- cos²a/sin a cos a) (sin a - 1/sin a) = - cos a
(sin² a / cos a sin a) (sin a- 1/sin a) = - cos a
(sin a/ cos a) (sin a- 1/sin a) = - cos a
sin² a/ cos a - 1 / cos a= - cos a
- (1 - sin²a) / cos a = - cos a
- cos ² a / cos a = - cos a
- cos a = - cos a (terbukti
sin(90-a) = cos a
Dan,
sin²a + cos²a = 1
Maka,
Nomor 1. (Sedikit terjadi kesalahan pada soal sepertinya)
Nomor 2. (Terbukti)