When x-> At 1, the denominator tends to 0, the numerator tends to 3, and the limit is infinite;

When x-> At -2, the denominator tends to -3, the numerator tends to 0, and the limit is infinitely small;

2)y=e^(-x)= 1/e^x

When x- > is +∞, the denominator tends to +∞, the numerator remains unchanged, and the limit is infinitely small;

When x-> -∞, the denominator tends to 0, the numerator remains unchanged, and the limit is infinite;