## steel11 3 years ago differentiate 9sec6x do i have to use both product and chain rules?

1. pitankar

yes!

2. steel11

somebody mind so it as well so i can see how its done? derivative of sec is secxtanx and thats messing me up

3. steel11

doing it as well*

4. pitankar

convert the secx to 1/cosx, that should help. And secx.tanx =sinx

5. oldrin.bataku

What is the function you wish to differentiate? \[\ \ \ \ 9\sec{x} * 6x\\ = 54x\sec{x}\tan{x} + 54\sec{x}\\ = 54\sec{x}\ [x\tan{x} + 1]\]

6. steel11

when i replaced sec6x with 1/cos6x, this is what i got as my final answer, still wrong though. (0*1/cos6x)+(9+1/-sinx*6)

7. pitankar

I guess you made a mistake in writing the post, it says secx6x, the function is sec6x???

8. steel11

oh wow, your right. my fault. differentiate 9sec6x

9. pitankar

use the chain rule only!

10. steel11

ah. so it was a chain rule only problem? or could it be done using both product and chain?

11. steel11

ugh. i just copied pasted your exact answer, says it was wrong. ._.

12. steel11

still keeps saying incorrect. >.<

13. pitankar

I crossed check, the answer indeed is 54*sec6x*tan6x. Just see if the equation was properly written. I mean I wrote 54sec6x.tan6x, try using 54*sec(6x)*tan(6x). hope that would work

14. steel11

yep, was written wrong, thank you for helping me these past 15-20 minutes!

15. pitankar

^_^