(cos 15+ sin 45) / (sin 60+cos 45) =

nilai fungsi trigonometri
(cos 15 + sin 45) / (sin 60 + cos 45) =
.
cos 15= cos (45-30) = cos 45 sin 30 - sin 45 cos 30
cos 15 = (1/2√2 . 1/2 - 1/2√2 .1/2 √3
cos 15  = 1/4 (√2 - √6)
.
(cos 15 + sin 45)/(sin 60 + cos 45)=
= (1/4√2 -1/4√6 + 1/2√2) / (1/2 √3 + 1/2 √2) ....(kalikan 4/4)
= (√2 - √6 + 2√2) / (2√3 + 2√2)
= (3√2 - √6)/(2√3 + 2√2)
atau ...(*kalikan  (2√3 - 2√2)/(2√3 - 2√2))

= (3√2 - √6)(2√3 - 2√2) / (12 - 8)
= (6√6 - 12 - 2√18 + 2√12) / (4)
= (6√6 - 12 - 6√2 + 8√3) / (4)
= 3/2 √6 - 3 - 3/2 √2 + 2√3