Logx=t
1/5-t+2/1+t
1+t+10-2t=(5-t)(1+t)
11-t=5+4t-t^2
t^2-5t+6=0
D=5^2-4*1*6=1^2
t=3
t=2
Lgx=3
X=1000
Lgx=2
X=100
Cos(п/2-х)-sin3x+sin5x=0
sinx-sin3x+sin5x=0
2sin(x+5x/2)cos(x-5x/2)-sin3x=0
2sin3x*cos2x-sin3x=0
sin3x(2cos2x-1)=0
sin3x=0
3x=Пn,n€z
x=пn/3,n€z
2cos2x-1=0
cos2x=1/2
2x=+-п/3+2пn,n€z
x=+-п/6+пn,n€z
1) 1 целая 2/5 * 2 целых 2/3 = 7/5 * 8/3 = 56/15
2) 1 целая 2/3 * 3 целых 1/2 = 5/3 * 7/2 = 35/6
3) 56/15 - 35/6 = -63/30 = - 2,1
3=a1+5*(-2) a1=13 S=(26-4)*3/2=33