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1
(cos(720+60)-ctg(540-45))*sin(180+45)=(cos60-ctg(-45))*(-sin45=
=(1/2+1)*(-√2/2=-3√2/4
-sin(4π-π/4)*tg(3π+π/6)=sinπ/4*tgπ/6=√2/2*√3/3=√6/6
2
2sina/(-sina)=-2
1
3x²+3x-16x+14=0
3x²-13x+14=0
D=169-168=1
x1=(13-1)/6=2
x2=(13+1)/6=7/6
2
ОДЗ
x∈(-∞;0]
x1=0
x²+6x+72=0
D=36-288=-252<0⇒x-любое
x²+4x-5=0
x2+x3=-4 U x2*x3=-5
x2=-5
x3=1не удов усл
X+10x=346;
11x=346;
x=346:11
x=считай дальше сама