In general: For an exponential function whose exponent tends to +- oo±∞ as x->oox→∞, the function tends to oo∞ or 0 respectively as x->oox→∞.
Note that this applies similarly for x->-oox→−∞ Further, as the exponent approaches +-oo±∞, minute changes in xx will (typically) lead to drastic changes in the value of the function.
Note that behavior changes for functions where the base of the exponential function, i.e. the aa in f(x) = a^xf(x)=ax, is such that -1<=a<=1−1≤a≤1.
Those involving -1<=a<0−1≤a<0 will behave oddly (as the f(x)f(x) will not take on any real values, save where xx is an integer), while 0^x0x is always 0 and 1^x1x is always 1.
For those values 0<a<10<a<1, however, the behavior is the opposite of the long-term behavior noted above.
For functions a^xax with 0<a<10<a<1, as x->oox→∞, f(x) ->0f(x)→0, and as x->-oox→−∞, f(x) ->oof(x)→∞