- #26

Mark44

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You need parentheses around the exponent. This is what you wrote:Thank you for your reply!

I am having trouble with the exercise f(x) = 3x^2/3 - 2x ; (-1,1)

f(x) = ## \frac{3x^2}{3} - 2x##

This is what I think you meant

f(x) = 3x

^{2/3}- 2x

Without using LaTeX or the HTML tags that I used, you can write it this way:

f(x) = 3x^(2/3) - 2x

But -1 and 1 aren't in the domain.I already found (-1,5) and (1,1) by plugging the intervals back into the function.

Again, you need parentheses. This is f'(x) = 2x^(-1/3) - 2But I have f'(x) = 2x^-1/3 -2 = 0

From an earlier post:Now, I am having trouble finding the answer. I found 1 which would give me (1,1).

However, the answer should be MIN (0,0) and MAX (-1,5). And I don't understand it.

Maxima or minima can occur at these places:

1. Numbers in the domain at which the derivative is zero.

2. Numbers in the domain at which the original function is defined, but the derivative is undefined.

3. Endpoints of the domain.