nilai sin 105°+cos 15° adalah

sin 105 + cos 15
= sin {60 + 44} + cos { 45-30}
= { sin 60 cos 45 + cos 60 sin 45 + { cos 45 cos 30 + sin 45 sin 30 }
= { 1/2√3 × 1/2√2 + 1/2 × 1/2√2 } + { 1/2√2 × 1/2√3+1/2√2 × 1/2 {
= 1/4 { √6 + √2 } + 1/4 { √6+√2 }
= 1/2 { √6 + √2 }
jika salah kak >_<.