A:три предложения
B:три предложения
С: три предложения
На английском​

Сначала формулы . затем формулы двойного угла sin2α=2sinαcosα cos2α=cos²α-sin²α=cos²α-(1-cos²α)=2cos²α-1⇒  2cos²α=1+cos2α cos2α=cos²α-sin²α=1-sin²α-sin²α=1-2sin²α⇒  2sin²α=1-cos2α а) сos75°cos105°=cos(90°-15°)·cos(90°+15°)== sin15°(-sin15°)=-sin²15°=-(1-cos30°)/2=(cos30°-1)/2= ((√3/2)-1)/2=0,25√3-0,5б) sin75°sin15°=°sin(90°-15°)sin15°=cos15° sin15°=sin30°/2=1/4=0,25в) sin105°cos15°=sin(180°-75°)cos15°=sin75°cos15°=sin(90°-15°)cos15°=cos15°cos15°=(1+cos30°)/2=(1+(√3/2))/2=0,5 +0,25√3 2 способ формулы cosα·cosβ=0,5cos(α-β)+0,5cos(α+β) sinα·sinβ=0,5cos(α-β)-0,5cos(α+β) sinα·cosβ=0,5sin(α+β)+0,5sin(α-β) а) сos75°cos105°=0,5cos(75°-105°)+0,5cos(75°+105°)=0,5cos(-30°)+0,5 cos180°==0,5· √3/2+0,5·(-1)=0,25√3-0,5б) sin75°sin15°=0,5cos(75°-15°)-0,5cos(75°+15° )=0,5cos60°-0,5 cos90°=0,5·0,5=0,25в) sin105°cos15°=0,5sin(105°+15°)+0,5sin(105°-15°)= =0,5sin120°+0,5sin90°==0,5 sin(180°-60°)+0,5·1=0,5 sin 60°+0,5=0,25√3+0,5

The Benjamin Franklin Prize, awarded for students who demonstrate excellence in their contributions to the school life, will be a new award in our school. This new Prize will be given out at the end of every school year to one student within the school. In order to receive the Benjamin Franklin Prize one must contribute to the well being of the school not only on the physical level, but also mentally. Some of the criteria in determining the winner will include his or her contributions to the student body in academic, athletic, and extracurricular activities. These activities can include, but not be limited to, football, chess club, artistic competitions, and academic olympiads. A possible winner of this award could be [Вставь имя одноклассника(ов)], as they contributed to the well being of the school in many different ways on the academic and social level. The award ceremony for the Benjamin Franklin Prize will take place in late May towards the end of the school year. It will be held outdoors in a local park to contribute to the atmosphere of serenity and societal wellbeing.

Слова не считал но примерно 150