I dont know. and right now, I asked my friend n she say
it is suppose to be:
d) = -2
f) = DNE
Now I am confused. Am I right, or is she right?
My answer is now
f) -1 (But I don't understand why it is -1)
There is no limit at . You can easily see in the graphic that the broken curves (the ones on the right and left hand sides of ) does not become arbitrarily closer to each other at (as it happens for ).
I guess Plato made a typo, check your answer for d, it must be .
Check the lines above by following the color order: red, yellow, green, blue and pink, as the vertical lines approach to from left, the horizontal lines approach to .