РЕШИТЕ, ПОЖАЛУЙСТА ,В1,В3, С1-С2. ЗАДАНИЕ ВО ВЛОЖЕНИИ, 1 ВАРИАНТ

B1
(sin55sin9-cos55sin(90-9))/(cos32-cos58)(cos32+cos58)=
=(sin55sin9-cos55cos9)/2sin13sin45*2cos13cos45=
=-cos64/(2/2*2/2*sin26)=-2cos64/sin(90-64)=-2cos64/cos64=-2
B3
1/2*sinx(16-x)=0
ОДЗ  (4-х)(4+х)0x[-4;4]
16-x=0x=-4 U x=4
sinx=0x=n+ОДЗx=-;0;
C1
(1-cos/6)/4+(1-cos7/6)/4+(1-cos5/6)/4+(1-cos11/6)/4=
cos7/6=-cos/6    cos5/6=-cos/6    cos11/6=cos/6
=(1-cos/6)/4+(1+cos/6)/4+(1+cos/6)/4+(1-cos/6)/4=
=1/2(1-2cos/6+cos/6+1+2cos/6+cos/6)=1/2(2+2cos/6)=
=1+cos/6=1+1/4=1,25
C2
2cosy-1+4acosy+2a+1=0
2cosy+4acosy+2a=0
2(cosy+2acosy+a(=0
2(cosy+a)=0
cosy+a=0
cosy=-a
-alt;-1agt;1 U -agt;1alt;-1
a(-;-1) U (1;)