differentiating

Hello, I am trying to understand how this was differentiated:
1/3x^3

I would have thought:
-3x^-3
9x^-4
9/x^4

but I know this wrong.
Can someone please point out where I am going wrong ?

Thanks kindly.

Quote:

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Originally Posted by fran1942

Hello, I am trying to understand how this was differentiated:
1/3x^3

I would have thought:
-3x^-3
9x^-4
9/x^4

but I know this wrong.
Can someone please point out where I am going wrong ?

Thanks kindly.

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Is it 1/(3x^3) ??

Then it's (1/3)x^-3, the derivative is
-3(1/3)x^-4 = -1x^-4 = -1/x^4

Quote:

---

Originally Posted by fran1942

Hello, I am trying to understand how this was differentiated:
1/3x^3

I would have thought:
-3x^-3

---

This is your mistake. [itex]1/3= 3^{-1}[/itex], not [itex]-3[/itex]
9x^-4
9/x^4

but I know this wrong.
Can someone please point out where I am going wrong ?

Thanks kindly.[/QUOTE]