Stupid Question but i need help : suppose i have "y= - ln x".......wat is the x intercept of that? i get (1,0)

Question

the equation is y = - ln x. I keep on getting -e^y=-x and i keep getting the x intercept is (1,0). My book says it's (-1,0). How do you get it algebraically? Thx!

Also! what is the X int of y= - ln (-x)?

Answer 1

y = -ln(x).

The x intercept is when y=0.

0 = -ln(x) is the same as
0 = ln(x)
which is when x = 1

(the log of 1 in any base is 0)

when x = 1, y=0
therefore, the intercept is (1, 0).

x = -1 is not in the domain.
Logarithms of negative numbers do not exist in the real numbers (there is a way to concoct them in the complex field, using the complex definition of logarithms).
In the graph, there would be no points on the left side of the y axis (meaning: no negative values of x).
Therefore, I don't see how the book could get (-1, 0) for the x intercept.