Match the pictures with the names . You can ask your parents to help you .

Sin2x = sin(π/2+x)
2sinxcosx = cosx
2sinxcosx - cosx = 0
cosx(2sinx - 1) = 0
1) cosx = 0
x = π/2 + πn , n∈Z
2) 2sinx - 1 = 0
sinx = 1/2
x = (-1)^n* π/4+ πn, n∈Z
Ответ: x = π/2 + πn , n∈Z  и  x = (-1)^n* π/4+ πn, n∈Z

13+15+10+8=46
2+5+3+2=12

 Если имелась ввиду дробь 11/12 то 990/1080