1) cos³x - cosx = 0
cosx*(cos²x - 1) = 0
a) cosx = 0
x₁ = π/2 + πk, k∈Z
b) cos²x - 1 = 0
cos²x = 1
cosx = - 1
x₂ = π + 2πn, n∈Z
cosx = 1
x₃ = 2πm, m∈Z
2) sin²x - 3sinx = 0
sinx(sinx - 3) = 0
a) sinx = 0
x₁ = πk, k∈Z
b) sinx - 3 = 0
sinx = 3 не удовлетворяет условию: IsinxI < 1
56=7*8 42=6*7
8*7*m^5n^7/6*7*m^5n^10=4/3m^5n^3
16d²+8d+1 = 16 (d²+ 1/2 d + 1/16) =
= 16 (d²+ 1/4d+1/4d + 1/4*1/4) =
= 16 (d (d+1/4) + 1/4 (d+1/4) )=
= 16 (d+1/4 )(d+1/4)
или
16d²+8d+1= (4d+1)²= (4d+1)(4d+1)
1 + ctq²x=1/sin²x;
1+ctq²x =1/(8/√65)² ;
ctq²x =65/64 -1;
ctq²x =164;
ctqx =1/8 ( 0<x<π/2 ctqx> 0 ).