X²+px+16=0 имеет единственный корень => D=0
D=p²-4*1*16=p²-64
D=0
p²-64=0
p²=64, p>0
p=8
x²+8x+16=0
(x+4)²=0
x+4=0
x=-4
X=π/3+y
(1+cos2x)/2+(1+cos2y)/2=-3/4
2+cos2x+cos2y=-3/2
cos2x+cos2y=-7/2
2cos(x+y)*cos(x-y)=-7/2
cos(x+y)cos(x-y)=-7/4
cos(2y+π/3)cosπ/3=-7/4
1/2cos(x+y)=-7/4
cos(x+y)=-7/2
нет решения,т.к. -7/2∉[-1;1]