A (a-2)(a+2)=a (a в квадрате -4)=а в 3 степени -4а
|2x+2|=4x+1 решите ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Gluckspilz
|2x+2|=4x+1
Уравнение равносильно системе:
{4x+1>=0
{2x+2=4x+1 U 2x+2=-(4x+1)
Решим систему:
1)4x+1>=0; 4x>=-1; x>=-1/4
2)2x+2=4x+1
2x-4x=1-2
-2x=-1
x=1/2
3)2x+2=-(4x+1)
2x+2=-4x-1
2x+4x=-1-2
6x=-3
x=-1/2 - не подходит по ОДЗ
Ответ:1/2
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А) sin(45+30)=sin45cos30+sin30cos45=sqrt(2)/2*sqrt(3)/2+1/2*sqrt(2)/2=(sqrt(3)+1)/(2*sqrt(2))
б) cos(135/2)=sqrt((1+cos135)/2)=sqrt{(1-sqrt(2)/2)/2}=sqrt((2-sqrt2)/4)=(sqrt(2-sqrt2))/2
1/sinx + 1/cos(7π/2 + x)=2
1/sinx + 1/cos(3π/2+2π+x)=2
1/sinx +1/cos(3π/2+x)=2
1/snx + 1/cos(π/2+π+x)=2
1/sinx + 1/(-cos(π/2+x))=2
1/sinx +1/sinx=2
2/sinx=2sinx | *(1/2 *sinx);sinx≠0
sin^2 x=1
|sinx|=1
sinx=-1 ili sinx=1
x=-π/2+2πn x=π/2+2πn
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x⊂[-5π/2; -π]
-5π/2 ≤-π/2+2πn≤-π -5π/2≤π/2+2πn≤-π
-5π/2+π/2≤2πn≤-π+π/2 -3π/(2π)≤n≤ -π/(2π)
-4π/2≤2πn≤-π/2 -1,5≤n≤ -1/2 ; n-celoe
(-2π)/(2π)≤n≤-π/(2*2π); n=-1
-1≤n≤-1/4 x=π/2-2π; x=-3π/4
n=-1 -----------
n=-1; -π/2-2π=-5π/2
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