(a) $\lim\limits_{t\to-\infty}\, (\frac{1}{t^{2}}+3) =$
(Enter the word infinity or -infinity if the limit goes to $\infty$ or $-\infty$.)

(b) $\lim\limits_{t\to\infty}\, 3\frac{1}{y} =$
(Enter the word infinity or -infinity if the limit goes to $\infty$ or $-\infty$.)