- #1
Sam
- 14
- 0
The problem: Find the inflection points, if any, for the following: f(x) = e^x + x^-1
I know to find inflection points I have to:
1. Compute f''(x)
2. Determine the points in the domain of f for which f''(x) = 0 or f''(x)
does not exist
3. Determine the sign of f''(x) to the left and right of each point x = c
found in step 2. If there is a change in the sign of f''(x) as we move
across the point x = c, then (c, f(c)) is an inflection point of f.
Well, this is what I came up with:
f'(x) = e^x -x^-2
f''(x)= e^x + 2x^-3
Then, I don't know what to do from there because e^x can never be zero, right? but I don't know. My teacher is saying there are inflection points...
Your help is much appreciated!
Sam
I know to find inflection points I have to:
1. Compute f''(x)
2. Determine the points in the domain of f for which f''(x) = 0 or f''(x)
does not exist
3. Determine the sign of f''(x) to the left and right of each point x = c
found in step 2. If there is a change in the sign of f''(x) as we move
across the point x = c, then (c, f(c)) is an inflection point of f.
Well, this is what I came up with:
f'(x) = e^x -x^-2
f''(x)= e^x + 2x^-3
Then, I don't know what to do from there because e^x can never be zero, right? but I don't know. My teacher is saying there are inflection points...
Your help is much appreciated!
Sam