Final answer:
The vertical asymptote of the function y = ln(x+1) is x = -1, as this is the value at which the function is undefined and the logarithm argument equals zero.
Step-by-step explanation:
The vertical asymptote of the function y = ln(x+1) can be found by determining the input values that would cause the function to approach infinity, which is characteristic of asymptotes.
For the natural logarithm function (ln), the argument must be greater than zero because the logarithm of zero or a negative number is undefined.
Therefore, the vertical asymptote occurs at the x-value that makes the argument zero. In the case of y = ln(x+1), this happens when x+1 = 0, or x = -1. This means that x = -1 is the vertical asymptote for the given function.