1) cos(1-x)=1/2 2)cosx/4=4/5 3)tg2x=3 4)tg(3x+)= 3/2

   1)

• cos(1 - x) = 1/2;
• cos(x - 1) = 1/2;
• x - 1 = /3 + 2k, k Z;
• x = 1 /3 + 2k, k Z.

   2)

• cos(x/4) = 4/5;
• x/4 = arccos(4/5) + 2k, k Z;
• x = 4arccos(4/5) + 8k, k Z.

   3)

• tg2x = 3;
• 2x = /3 + k, k Z;
• x = /6 + k/2, k Z.

   4)

• tg(3x + 1) = 3/2;
• 3x + 1 = arctg(3/2) + k, k Z;
• 3x = arctg(3/2) - 1 + k, k Z;
• x = arctg(3/2)/3 - 1/3 + k/3, k Z.

   Ответ:

• 1) 1 /3 + 2k, k Z;
• 2) 4arccos(4/5) + 8k, k Z;
• 3) /6 + k/2, k Z;
• 4) arctg(3/2)/3 - 1/3 + k/3, k Z.