dx The equilibrium points of the system =(2+x) (y-x), dy = (4-x)(y+x) are dt a) (0,0), (-2,2), (4,4) b) (0,0), (2,-2), (-4,4) c) (0,0), (2,-2), (4,-4) d) (0,0). (2-2). (-4,-4) -/ dx αν The suitable Liapunov function for the system =-2x²y-y³ is dt a) V(x,y)=x+y² b) V(x,y)=x+2y² c) V (x,y) = 2x² + y² d) V (x, y) = x² + y² The Fourier Cosine series of the function f(x)=3-x, 0<x<3 is 00 3 6 1-cos (nл) == + ηπ cos a) f(x) = π n² b) f(x) =Σ 1- cos(nл) n² ηπ Cos ·x =1 c) f (x) = 3 + = 3 6 1- cos(nл) ₫) ƒ (x) = ¾³±±±² n² 1- cos(n) n² The solution to the equation a) z=27-5i 27 5 b) z=- 29 29 c) z=5-27i d) z=0+5i ηπ Cos x 3 2) cos(17x) COS 3 ηπ -=1-5i is 1-z