(6,9*10^-2)(5*10^-3)=(6,9*0.01)*(5*0.001)=0.069*0.005=0.000345
6 sin^2 x = 5 sin (3pi/2 - x) + 2;
6 sin^2 x = - 5 cos x + 2;
6 sin^2 x + 5 cos x - 2 = 0;
6(1- cos^2 x ) + 5 cos x - 2 = 0;
6 - 6 cos^2 x + 5 cos x - 2= 0;
6 cos^2 x - 5 cos x - 4 = 0;
D = 25+144= 121= 11^2;
cos x = (5+11)/12= 16/12= 4/3 > 1; нет решений.
сos x = - 1/2; x = + - pi/3 + 2pi*k; k-Z
(y+x)/(y-x)+5*(y-x)/(y+x)=6
(y+x)²+5*(y-x)²=6*(y²-x²)
y²+2xy+x²+5y²-10xy+5x²=6y²-6x²
6y²-8xy+6x²=6y²-6x²
12x²-8xy=0 I÷4
3x²-2xy=0
x(3x-2y)=0
x₁,₂=0 0²+y²=13 y²=13 y₁=√13 y₂=-√13
3x-2y=0 3x=2y x=2y/3
((2/3)*y)²+y²=13
4y²/9+y²=13
13y²/9=13 I÷13
y²/9=1
y²=9
y₃=3 x₃=2*3/3=2
y₄=-3 x₄=-2*3/3=-2
Ответ: x₁=0 y₁=√13 x₂=0 y=-√13 x₃=2 y₃=3 x₄=-2 y₄=-3.