The y intercept is the point at which at which the graph cuts the x axis. At this point, x = 0
Thus, given that the function is expressed as
f(x) = 5^x, at x = 0
f(0) = 5^0 = 1
y intercept = 1
The x intercept is the point where y or f(x) = 0
It becomes
0 = 5^x
x = - infinity
The end behavior of a function is the behavior of the graph of f(x) as x approaches positive or negative infinity. For the end behavior of f(x), f(x) tends to - infinity as x tends to - infinity