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Calculus/Inflection Point

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Question
Does f(c)= (c+2)^3 -2 have an inflection point?  If so, where is it located?

a) Yes, at (-2, -2)
b) Yes, at (2, -2)
c) Yes, at (8, -2)
d) no

Answer
It is known that f"(c) = 0 at an inflection point.

It can be seen that f'(c) = 3(c+2)^2.

Now we have to multiply by the derivative of what is inside the parenthesis, but that is 1, so its been done already.

It can be seen that f"(c) = 6(c+2), so the second derivate is a line.
Not that it matters what the second derivative is, only where
f"(c) = 0.

Since there is an x + 2 in f"(c), we need x + 2 = 0,
which means that x = -2.

Putting -2 back into the function gives us
(-2 + 2)^3 - 2 = 0^3 - 2 = -2.

The answer is yes, (-2, -2).

Calculus

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