A(25-b^2)=a(5-b) (5+b)
3(a^2-2a+1)
1.7849629317 х 2.801178619 = 4 и 9 в периоде 4.(9) 》5
sin³x·cos x - cos³x·sin x = √3/8
sin x·cos x·(sin²x - cos²x) = √3/8
1/2 · sin 2x · (-cos 2x) = √3/8
2 · sin 2x · (-cos 2x) = √3/2
sin 4x = -√3/2
4x = (-1)ⁿ⁺¹·π/3 + πn, n ∈ Z
x = (-1)ⁿ⁺¹·π/12 + πn/4, n ∈ Z