Npocture bbipakehne [133, 134]. 33.1) sin? a + cos2 a + tg2 a; a)- tg a + ctg a ; 1-tg2 a 1-ctg2 a' sin a sin a 3) 1 + cos a + 1 - cos a: sinº a - cos4 a + cos2 a; 5) tg2 a cosa a + ctg2 a sin2 a; 6) cos4 a + sina a cos? a + sin? a. cos3 a - sin3 a.
1. do your parents let you go out in the evenings?
2. i am not allowed to go out on sunday nights.
3. are pupils at your school allowed to wear jeans?
4. our teacher does not let us eat in class.