Відповіді на вправи: 578

1) y_n = n + 1;

y₁ = 1 + 1 = 2;

y₂ = 2 + 1 = 3;

y₃ = 3 + 1 = 4;

y₄ = 4 + 1 = 5;

(y_n): 2; 3; 4; 5.

2) y_n = $\frac{2}{n+3}$;

y₁ = $\frac{2}{1+3}$ = $\frac{2}{4}$ = $\frac{1}{2}$;

y₂ = $\frac{2}{2+3}$ = $\frac{2}{5}$;

y₃ = $\frac{2}{3+3}$ = $\frac{2}{6}$ = $\frac{1}{3}$;

y₄ = $\frac{2}{4+3}$ = $\frac{2}{7}$;

(y_n): $\frac{1}{2}$; $\frac{2}{5}$; $\frac{1}{3}$; $\frac{2}{7}$.