## mathcalculus 2 years ago HELP DERIVATIVE:

1. mathcalculus

2. mathcalculus

how is the answer -7sqrt (6)/t^8?

3. mathcalculus

@BangkokGarrett

4. mathcalculus

@dan815

5. mathcalculus

i tried using the quotient rule .. but that didn't work

6. katherine.ok

so find derivative of sqrt(6)*t^-7?

7. mathcalculus

also the power rule... so what's next?

8. katherine.ok

-7(t^-8)sqrt(6)

9. mathcalculus

yes how did you get to the answer?

10. katherine.ok

make it first look like sqrt(6)*t^-7

11. mathcalculus

why?

12. katherine.ok

notice that sqrt (6) is constant. and t^-7 is the variable you are worrying about.

13. mathcalculus

can i not use the power rule then quotient rule?

14. katherine.ok

because this is simply exponent derivative,you not need to worry about quotient rule , power rule.

15. Jhannybean

$\large f(t) = \frac{\sqrt{6}}{t^7} = \sqrt{6}t^{-7}$$\large f'(t) = \sqrt{6} \cdot -7 t^{-7-1}$$\large f'(t) = -7 \sqrt{6}t^{-8}$$\large f'(t) = \frac{-7\sqrt{6}}{t^8}$

16. katherine.ok

power rule and quotient rule is applicable in more complicated setting where you have f(x)*g(x) .

17. mathcalculus

ohhhhhhh. right right. this is just simple derivative

18. mathcalculus

okay. thank you!

19. Jhannybean

You should know that $\large \frac{d}{dx} x^{n} =\frac{nx^{n-1}}{n-1}$