1/sina+1-1/sina-1=2Sec2a

Kl mo cepet direspon, ketik soal yg rapi dan mudah dipahami ya..
Gk kmu aja yg pengen dipahami..

▶ samakan penyebutnya
(sin a + 1)(sin a - 1) = sin² a - 1

1/(sin a + 1) - 1/(sin a - 1)
= ((sin a - 1) - (sin a + 1))/(sin² a - 1)
= -2/(sin² a - 1)
= 2/(1 - sin² a)
= 2/cos² a
= 2 sec² a
TerBukTi

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1/cos a = sec a

Identitas Trigonometri

1/(sin a + 1)   - 1/(sin a - 1)  = 2 sec² a
..
{1(sin a -1 ) - 1(sin a +1) }/ (sin a +)(sin a -1)  = 2 sec² a
( sin a - 1 - sin a - 1) / (sin² a -1) = 2 sec² a
(-2)/(- cos² a) = 2 sec² a
2 (1/cos a)²  = 2 sec² a
2 (sec a)² =   2 sec² a
2 sec² a = 2 sec² a
....
Tbukti