Sign chart for inflection points
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A sign chart for inflection points shows us the x-values of inflection in our function and how the concavity behaves surrounding them.
An inflection point is where the function changes concavity.
Scenario: Create a sign chart for inflection points of f(x) below.
Remember: we want to find the x-values for inflection points... a.k.a. where the concavity equals zero!
Now, we need to find whether f''(x) is positive or negative at each of those "?" values!
Plugging in any number less than 0...
...results in a negative concavity value, which we can plug into our sign chart like so:
Plugging in any number greater than 0...
...results in a positive slope value, which we can plug in like so.
