7/48+и/48=7/48
и/48=7/48-7/48
и/48=0
и=0
Сначала:
arcCos√3/2 = π/6
arcSin√2/2 = π/4
arc tg √3 = π/3
Теперь решаем:
а) Cos(π + π/6) = -Сosπ/6 = -√3/2
б) Cos(π/2 - π/3) =Sinπ/3 = √3/2
в) 8Sin x = 7Cos x |: Сosx ≠0
8tg x = 7
tgx = 7/8
x = arctg(7/8) + πk, k∈Z
1) 2sin32*cos32/sin64 = sin2*32/sin64=sin64/sin64 = 1
2) -6sin32/sin16sin74 = -12sin32/2sin16cos16 = -12sin32/sin32 = -12
3) -9sin136/cos68*cos22 = -9sin136/cos68sin68= -18sin136/sin136 = -18
Дискриминант:
D=12^2 - 4*(-4)*7 = 144+112=256=16^2
корни:
х1 = (-b + {D})/2a = (12+16)/(-8) = -3,5
x2 = (12-16)/(-8) = 0,5