buktikan identitas berikut no 2 a, b, c ya.. makasih sebelumnya

a][
cot a + tan a
= cos a /sin a + sin a /cos a
samakan penyebut
= (cos² a + sin² a)/(sin a cos a)
= 1/(sin a cos a)
= 1/sin a . 1/cos a
= cosec a . sec a
TerBukTi

b][
(1 + sin A + cos A)²
= 1² + 2(1)(sin A + cos A) + (sin A + cos A)²
= 1 + 2(sin A + cos A) + (sin² A + cos² A + 2 sin A cos A
= 1 + 2sin A + 2 cos A + (1 + 2 sin A cos A
= 2(sin A + cos A + sin A cos A + 1)
= 2(sin A + 1)(cos A + 1)
TerBukTi

c][
cos² θ /(1 - sin θ)
= (1 - sin² θ)/(1 - sin θ)
= (1 - sin θ)(1 + sin θ) / (1 - sin θ)
= 1 + sin θ
TerBukTi