Вот держи. полное решение уравнения
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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В)у^2-5^у=0
y(y-5)=0
y=0
y-5=0
y=5
г)b^2+20b=0
b(b+20)=0
b=0
b+20=0
b= -20
в) 9m^2 + 0.27m = 0
m(9m + 0.27)=0
m=0
9m+0.27=0
9m=-0.27
m=-0.03
г)-7x^2+2x=0
x(-7x+2)=0
x=0
-7x+2=0
-7x=-2
x= -2/-7
в)x^3-3x^2 = 0
x^2(x-3)=0
x^2=0
x=0
x-3=0
x=3
Г) (x+4)^2-3x(x+4)=0
x^2+4x+16-3^2-12x=0
-2x^2-8+16=0
-2x^2=-8/(-2)
x^2=4
x=2