Question

упростите выражение sin 35° cos 20° - cos35°sin 20°
cos 44° cos29° + sin 44° sin 29°​

Answer 1

sin 35° cos 20° - cos35°sin 20° = sin(35°-20°) = sin15° = Sin(45°-30°) = sin 45° cos 30° - cos45°sin 30° = √2√3/4 - √2/4 = √2(√3-1)/4

cos 44° cos29° + sin 44° sin 29°​ = cos(44°-29°) = cos15° = cos(45°-30°) = cos 45° cos 30° + sin45°sin 30° = √2√3/4 + √2/4 = √2(1+√3)/4

Answer 2

Ответ:

sin(35-20)=sin15=√3-1/3√2

cos(44-29)=cos 15=√3+1/2√2