question

[hearty shuttle]

Question is what points of f arent differentiable. I got x = -4, -1, 4, and im thinking maybe x = 2 and 0. Are these right or no?

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[hearty shuttle]

I get that a point has to be continuous to be differentiable but is it also not differentiable at corners and when the derivative sign changes (e.g. at x = 0)

[vapid oxide]

x=0 is differentiable

[supple loom]

not x=0, because the function is "smooth" at that point, even though it peaks there

[hearty shuttle]

so then is x = 2 not differentiable? because its a sharp corner?

[supple loom]

yep

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