2sin²x+sinx=0 x ∈ {2*пи*k, 2*пи*k-5*пи/6, 2*пи*k-пи/6, 2*пи*k+пи}, k ∈ Z cos²x-2cosx=0 x ∈ {2*пи*k-пи/2, 2*пи*k+пи/2}, k ∈ Z; x ∈ {2*%pi*k-1167/3434}, k ∈ Z; x = (956884*%pi*k-630088*%i+751535)/478442;x = (197005462099694977024*%pi*k+1367*%i-275980585165263994880)/98502731049847488512;x = (956884*%pi*k+630088*%i+751535)/478442; k ∈ Z 6cos²x+7cosx-3=0 x ∈ {2*%pi*k-asin(2^(3/2)/3),2*%pi*k+asin(2^(3/2)/3)}, k ∈ Z; x = 2*%pi*k-%i*log(3-sqrt(5))+%i*log(2)+%pi;x = 2*%pi*k-%i*log(sqrt(5)+3)+%i*log(2)+%pi; k ∈ Z
2)(a³-b²)*(a³+b²)=a^6-b^4
3)(4a-b/2)*(4a+b/2)=16a²-b²/4
4)(2a/3-3b)*(2a/3+3b)=4a²/9-9b²
5)(2x+y+z)*(2x-(y+z))=4x²-(y+z)²
6)(x+y-2z)*(x+y+2z)=(x+y)²-4z²