докажите тождество, двойка после скобки это квадрат
1- ([email protected] - sin @)2= [email protected]
1 - ( [email protected] 2 - [email protected]@ + sin @2)= [email protected]
1 - [email protected] + [email protected]@ - [email protected] = [email protected]@
1 - [email protected] + [email protected]@ - [email protected] - [email protected]@ = 0
0=0
[email protected] (2 это квадрат)