Предмет: Математика, автор: creator2288

 Докажите тождество
2Cos квадрат t=1+Cos2t
2Sin квадратt=1-cos2t

Ответы

Автор ответа: nKrynka
0
Решение
2Cos² t=1+Cos2t
применим формулу:
cos2t = 2cos²t - 1,
2cos²t = 1 + cos2t
1 + cos2t = 1 + cos2t
доказано

2Sin ²t=1-cos2t
cos2t = 1 - 2sin²t
2sin²t = 1 - cos2t
1 - cos2t = 1 - cos2t
доказано
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The family in the modern society

Importance of family as institute of education is caused by the fact that the child is in it during a considerable part of the life, and on duration of the impact on the personality any of institutes of education can't be compared to family. In it the foundation of the identity of the child is laid, and to receipt in school he was already more than half created as the personality.

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My family is not very big, just a typical family: Dad, Mom, me, my brother and sister and our cat.

My Mummy is forty-one, she is a teacher of Spanish at the University.

She is a born teacher.

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Everyone in my family is my best friend.​
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