Question

Trigonometri sin
tolong ya .. ntr dpt jawaban tercerdas. soal ny yg pake pena

Answer 1

(sin² 1° + sin² 89° ) + ( sin²2° + sin² 88°)+........+ ( sin²44° + sin²46°)+sin²45°
= ( cos²89°+sin²89²)+(cos²88° + sin²88°)+........+(cos²46° + sin²46°)+ sin²45°
= 1+1+1+1.....+1+1/2

= 44 + 1/2
= 89/2

Answer 2

Sin^2 A + Cos^2 A = 1
Sin A = cos B jika A + B = 90°
Sin 89 = cos 1
Sin 88 = cos 2
Sin 87 = cos 3
Sampai
Sin 46 = cos 44
Jadi
Sin^2 1 + sin^2 2 + sin^2 3 + ........ + sin^2 87 + sin^2 88 + sin^2 89
= Sin^2 1 + sin^2 2 + sin^2 3 + ........ + cos^2 3 + cos^2 2 + cos^2 1
= sin^2 1 + cos^1 + sin^2 2 + cos^2 + sin^2 3 + cos^2 3 + ...... + sin^2 44 + cos^2 44 + sin^2 45
= 1 + 1 + 1 + ...... + 1 + sin^2 45
= 1 . 44 + (1/2 √2)^2
= 44 + 1/2
= 44 1/2 atau 89/2