Sunday

January 25, 2015

January 25, 2015

Posted by **Alex** on Saturday, November 6, 2010 at 8:39pm.

- Calc -
**Reiny**, Saturday, November 6, 2010 at 10:09pmI read your statement as

f(x) = 12x^(2/3) - 4x

then

f '(x) = 8x^(-1/3) - 4

= 0 for max/min

8/x^(1/3) = 4

4x^(1/3) = 8

x^(1/3) = 2

x = 8

then f(8) = 12(8)^(2/3) - 4(8)

= 48 - 32

= 16

Can you take it from here?

remember that the function is concave up when the second derivative is positive and

concave down .....

- Calc -
**Anonymous**, Sunday, January 4, 2015 at 1:09pmWhen the second derivative is negative

**Answer this Question**

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