(x-1)(x+1)<2(x-1)
x=1 x=-1<x=0 x=1
x³-x²-x²-6x+x+6=0
x²(x-1)-6(x-1)-x(x-1)=0
(x-1)(x²-6-x)=0
x1=1
x²-x-6=0
D= 1+24=25
x2= (1+5)/2= 3
x3= (1-5)/2= -2
Ответ: x1= 1, x2= 3, x3= -2
<span>a) sin 13п/6 =sin(12</span>π/6+π/6)=sin(2π+π/6)=sin π/6=1/2=0.5
<span>б) tg (-11п/6) =-tg(11</span>π/6)=-tg(12π/6-π/6)=-tg(2π-π/6)=tgπ/6=√3/3
<span>в)cos п + ctg 4п/3 =-1+</span>√3/3
<span>г)tg п/4 ctg (-п/4) + cos 3п/2 sin п/2 =-tg </span>π/4*ctg π/4+0*1=-√2/2*√2/2+0=-2/4=-1/2=-0.5
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д) sin 405º + cos 225º tg 225º=sin(360+45)+cos(180+45)*tg(180+45)=sin45+(-cos45)*tg45=</span>√2/2-√2/2*1=0