(b) let the systen of differential equations be given by \[ \frac{d x}{d t}=-x y+x(1-x) \] \[ \frac{d y}{d t}=-3 x^{2} y+2 y\left(1-\frac{y^{2}}{2}\right) \] (i) Determine the \( x \)-isoclines and \( y \) - isoclines and the signs of \( \frac{d x}{d t} \) and dy/dt. (ii) Determine the equilibrium points of the system. (iii) Deteormine the stability of the equilibrium points.

7 A circle has centre \( (2,-7 j, P Q \) is a diameter of the circle, where \( P \) is the point \( (a,-5) \) and \( Q \) is the point \( (8, b) \). Find the values of a and

2393. Sono dati gli insiemi \( A=\{a, b, c\}, B=\{b, c, d, e\} \). Scrivi le rappresentazioni, per elencazione, degli insiemi: \( \begin{array}{llll}\text { a. } A \cap B & \text { c. } A-B & \text { e. }(A \cap B) \times(A-B) & \text { g. }(A \cap B) \times(B-A) \\ \text { b. } A \cup B & \text { d. } B-A & \text { f. }(A-B) \times(A \cap B) & \text { h. }(A-B) \times(B-A)\end{array} \)

Dehil \( =C \times 3 x \)

81. \( \frac{4 \cos ^{3} \omega-\cos \omega}{3 \operatorname{sen} \omega-4 \operatorname{sen}^{3} \omega} \)

\( \leftarrow \) For the function, \( f(x)=x^{2}+6 x+4 \), complete parts a through \( c \). a) \( f(x+h)=\square \) (Simplify your answer.)