Помогите решить задание по тригонометрии пожалуйста!

корень из трех cosx - 1/2sinx =cos3x

ответте пож на вопросы
1. What in your view makes parents think that taking drugs is the worst problem teenagers have? Are their fears justified?
2. At what age do friends become of great importance for a child? Does the role of friends change while a child is growing?
3. Are friends as important at an older age as when one is young? Why (not)?
4. Do you agree that having a group of friends is more attractive and safer than having just one close friend?
5. In your experience do big groups of friends tend to fall into couples? Is it natural?
6. Do you think friendship is more important than love? Why (not)?
7. What does friendship give you? Would you like to keep your friends through your life?
8. Are you afraid of being lonely or do you prefer to keep your own company?
9. What should a good friend be like? What weaknesses can you forgive in your friends? How do you understand the saying "Love is blind but friendship closes its eyes"?
10. Can you give an example of true and faithful friends? What makes them such friends?
11. Can you comment on the proverb "A friend in need is a friend indeed"?

Вася обычно поднимался по движущемуся вверх эскалатору, шагая со скоростью 1 ступенька в секунду, и через 20 шагов, оказывался наверху. Однажды он торопился, шагал через ступеньку (2 ступеньки в секунду) и оказался наверху, пройдя 32 ступеньки. Сколько ступенек в эскалаторе?

ABCD -ромб

AB=5см

BD=6см

OK=8см

K перпендикулдярна  (ABC)

Найдите  KA,KB,KC,KD

ПОМОГИТЕЕЕ, ПЛИИИЗ!!! СОЧИНЕНИЕ.почему вам понравилась повесть бедная лиза и что вы считаете в ней устаревшим если можно полным ответом в инете ни где нет.