Аааа, помогите 8 × sin(5°) × cos(5°) × cos(10°) / cos(70°)

Question

Аааа, помогите
8 × sin(5°) × cos(5°) × cos(10°) / cos(70°)

Answer 1

4.2.sin 5.cos5 .cos10/c0s70 = 4.sin10.cos10/cos70 = 
2.2.sin10.cos10/cos70 = 2. sin20./cos70=
2.sin20/sin20 = 2

Comments

Formula: sin 2x = 2.sinx.cos , cos (90-x) = sinx