16^2+8x+1=0
D=8^2-4*16*1=64-64=0
x=-8/2*16=-0.125
2x^2-9+4
5a^2+216a-24=0
D=216^2-4*5*(-24)=
7x^2-2x+12=0
D=(-2)^2-4*7*12=4-336=-332 отриц не может быть
3x^2-5x=0
x(3x-5)=0
x=0
3x-5=0 3x=5 x=5/3
1) <span>ctg x - tg x = (cos x - sin x) / (1/2*sin 2x)
x ∈ {2*пи*k, 2*пи*k-1065/452}, k ∈ Z
2) </span><span>sin^2 x *(tg x+1)+3sin(cos x - sin x)+3=0</span><span>
x ∈ ∅
</span>
2) cosx-√3sinx=√2 |:2
½cosx-√3/2sinx=√2/2
½=sin(π/6); √3/2=cos(π/6)
sin(π/6)cosx-cos(π/6)sinx=√2/2
sin(x-π/6)=-√2/2
x-π/6=(-1)^n•arcsin(-√2/2)+ πn
x-π/6=(-1)^(n+1)•arcsin(√2/2)+ πn
x=(-1)^(n+1)•π/4+π/6+ πn