1
сtg3x-ctgx=0
sin(3x-x)/sin3x*sinx=0
sin2x=0 U sin3x*sinx≠0
2x=πn⇒x=πn/2,n∈z U x≠πk,k∈z U x≠πm/3,m∈z
x=πn/2,n∈z U n≠2m/3,m∈z
3
sin(2x+4x)/cos2xcos4x=sin(5x+x)/cos5xcosx
sin6x/cos2xcos4x-sin6x/cos5xcosx=0
sin6x(cos5xcosx-cos2xcos4x)/cosxcos2xcos4xcos5x=0
cosxcos2xcos4xcos5x≠0
sin6x=0⇒x=πn/6,n∈z
cos5xcosx-cos2xcos4x=0
1/2*cos4x+1/2*cos6x-1/2*cos2x-1/2*cos6x=0
1/2*cos4x-1/2*cos2x=0
-1/2*2sinxsin3x=0
sinx=0⇒x=πk,k∈z
sin3x=0⇒x=πm/3,m∈z
(cos pi/4*cos 2x + sin pi/4*sin 2x) - √2sinx = √2(sin2x + 1)
2(√2/2*cos 2x + √2/2 *sin2x) - √2sinx = √2(sin 2x +1);
2*√2/2 (cos 2x + sin 2x) - √2sinx = √2(sin 2x +1);
cos2x + sin 2x -sinx = sin 2x +1;
1 - 2sin^2 x - sinx = 1;
-sinx(2sinx+1)=0;
1) sinx = 0; x1=pin, n---Z.
2) 2sinx+1=0; sinx= -1/2; x2=(-1)^n(-pi/6)+pin, n---Z.
10 га = 70*10 = 700 т
100 га = 70*100 = 7000 т
m га = 70m т
16000 = 70*16000 = 1120000 т
х=-2.4 f(-2.4)=-2.4*4=-9.6
f(3.5)=4*3.5=14