search

mooculus / calculus

http://mooculus.osu.edu/
Other
136 stars 430 forks source link

missing a critical point #951

Closed pfatheddin closed 6 months ago

pfatheddin commented 6 months ago

See maximumsAndMinimums/exercises/maxMinSecondDerivativeTest4.tex

https://ximera.osu.edu/mooculus/maximumsAndMinimums/exercises/exerciseList/maximumsAndMinimums/exercises/maxMinSecondDerivativeTest4?

Here it says the function only has one critical point: image

But if you find the derivative you get: image They have 8/3 but also need 4 since by definition is a critical point.

bwramsey commented 6 months ago

The point at x=4 does NOT satisfy the definition of being a critical point. (Not an interior point of the domain.)