Tentukan nilai dari 1+sin 15°/1-sin15 °

jawab
sin 15 = sin (45-30)
= sin 45 cos 30 - cos 45 sin 30
= 1/2 √2 . 1/2 √3  - 1/2 √2 . 1/2
= 1/4 √ 6 - 1/2√2


(1 + sin 15) /(1 - sin 15) =
= (1+ 1/4 √6 - 1/2 √2) / (1 - 1/4 √6 + 1/2 √2)
= 1/4 (4 + √6 - 2√2) / 1/4 ( 4 - √6 + 2√2)
= (4 + √6 - 2√2) / (4 - √6 + 2√ 2)