## burhan101 2 years ago Find the derivative

1. burhan101

$\huge y=(15d)e^{\frac{ -d }{ 5 }}$

2. cwrw238

6 penguins on board!

3. burhan101

$\huge y= (15d)'(e^{\frac{ -d }{ 5 }})+(15d)((e^{\frac{ -d }{ 5 }})'$

4. burhan101

y'= *

5. Azteck

Are you differentiating with respect to d or x?

6. Azteck

Or is d a constant?

7. Azteck

"d"*

8. burhan101

$\huge y'= 15(e^{\frac{ -d }{ 5 }})-30d(e^{\frac{ -d }{ 5 }})$

9. Azteck

Ah sorry, my eyes went somewhere. Sorry about that.

10. burhan101

d is a constant :P

11. Azteck

d is the variable, not a constant.

12. Azteck

and you are almost correct. The 30 is not right.

13. cwrw238

14. cwrw238

(e^(-d/5)' = -(1/5)e*(-d/5)

15. Azteck

@burhan101 are you there? If you are, please read what cwrw238 has written above.

16. burhan101

@cwrw238 im a little confused

17. burhan101

|dw:1371805163917:dw| @Azteck @cwrw238

18. Azteck

$\frac{1}{5}\times 15=75???$

19. Azteck

I think you got confusde about 1/5 and 5 when multiplying.

20. Azteck

confused*

21. burhan101

oppps 3*

22. burhan101

|dw:1371805796678:dw|

23. burhan101

@Azteck

24. Azteck

Yep, excellent!

25. Azteck

Well done.

26. burhan101

One more question

27. burhan101

if i solve for d, will i have to use ln ?

28. burhan101

nvm i got it :P