## bmelyk 3 years ago Just want an answer checked: Find the derivative of the function given below. y = (3x4 – 3x + 5)^-3

1. bmelyk

$-3 x (\frac{ 4x^3-3 }{ (3x^4-3x+5)^-4 }$

2. bmelyk

that's not a -3x, it's -3 times the fraction.

3. hartnn

why is there 3x multiplied ?

4. hartnn

then you are correct!

5. bmelyk

yay~~~ :)

6. uzumakhi

there should be 12 x^3 in place of 4x^3

7. bmelyk

why?

8. bmelyk

it should be 12x^2 shouldnt it?

9. uzumakhi

can you write correct answer for us

10. bmelyk

12x^3, i see why.

11. hartnn

-3*(4x-3) will give -12x^3 +9 @uzumakhi

12. bmelyk

i didn't do out the derivative, i get it.

13. bmelyk

so i was right to begin with?

14. bmelyk

now im confused.. was my answer okay in the first place?

15. uzumakhi

$-3(\frac{ 12x ^{3}-3 }{ (3x ^{4}-3x + 5)^{4} })$

16. uzumakhi

17. hartnn

oh , yes.....sorry! u missed the 3 @uzumakhi is correct. sorry for confusion :(

18. bmelyk

no i have the same now because when you take the derivative of 3x^4-3x+5 it is 12x^3-3, i forgot to place my power rule on my 3x^4

19. uzumakhi

that i want to tell in begining

20. bmelyk

i gotcha!

21. uzumakhi