0,45m3x5y5
3 и 5, 5 с верху букв
4*3/8-9*7/9=6-7= -1. Ответ: -1.
Сos(x/2) = 1/2
x/2 = ±π/3 + 2πn, n ∈ Z
x = ±2π/3 + 4πn, n ∈ Z
0 < ±2π/3 + 4πn < 4π, n ∈ Z
n = 0
x₁ = 2π/3
n = 1
x₂ = - 2π/3 + 4π = 10π/3
Ответ:x = ±2π/3 + 4πn, n ∈ Z; 2π/3; 10π/3
найдем производную, она равна -9/x^2+1=(x^2-9)/x^2=(x-3)(x+3)/x^2