1)2 5/6:2 4/15=17/6:34/15=17/6*15/34=15/12=1,25
2)1,5*0,3=0,45
3)1,25-0,45=0,8
<span>4)-0,24:0,8=-0,3</span>
а) 0.125 или 1/8
б) 1/49
в) 1/6 + 1/4 = 2/12 + 3/12 = 5/12
Cos(π+x/2) =0 ;
π+x/2 =π/2+π*k , k∈ Z.
x/2 = - π/2 +π*k;
x= -π+2π*k;
x=(2k -1)π; нечетное число π
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sin(π/2+x) =1;
π/2+x =π/2 +2π*k;
x =2k*π. четное число π
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cos(π/3 -x) =√2/2;
cos(x-π/3) =√2/2;( cos четная фунлция)
x-π/3 =(+/-)π/4 +2π*
x₁= π/3+(+/-)π/4 +2π*k;
или
x₁ = 7π/12+2π*k;
x₂ = π/12+2π*k;
Кидаю все:).......................