It gives the corresponding f of x. What is a reasonable estimate for the limit of f of x as x approaches one from the left? So pause this video and see if you can figure it out on your own. Alright, now let's work through this together. So the first thing that is really important to realize is when you see this x approaches one and you see this little negative superscript here, this does not mean approaching negative one. So this does not mean negative one. Sometimes your brain just sees a one and that little negative sign there, and you're like, oh, this must be a weird way of writing negative one, or you don't even think about it.