## onegirl 2 years ago Find the derivative of f(x) tan 3x - csc 4x.

1. Twis7ed

So you mean$\frac{ d }{ dx }(\tan3x-4x)*\frac{ d }{ dx }(3x)*\frac{ d }{ dx }(4x)$?

2. onegirl

no the derivative of tan 3x - 4x...the multiplying part is the directions

3. onegirl

hold on wait its tan 3x - csc 4x

4. onegirl

its tan 3x- csc 4x i miss typed it

5. Twis7ed

6. Twis7ed

And what part of the equation is inside the tan? Is it tan(3x)-4x or tan(3x-4x)

7. onegirl

No not the correct answer i need to find the derivative of that and it says to multiply the derivatives of 3x and 4x into the promblem

8. onegirl

its tan 3x - csc 4x thats how it written

9. Hoa

@onegirl Please, post the right question. I confuse, too

10. onegirl

okay hold on

11. onegirl

let me edit my original question

12. onegirl

there do you guys see it now?

13. Hoa

yes. i think Twis7ed will guide you well.

14. onegirl

ok

15. Twis7ed

Oh, ok, so$\frac{ d }{ dx }(\tan 3x - \csc 4x)=\frac{ d }{ dx }\tan3x - \frac{ d }{ dx }\csc4x$ From that you know that $\frac{ d }{ dx }\tan3x = 3\sec^2(3x)$ and that $\frac{ d }{ dx }\csc4x=-4\cot(4x)\csc(4x)$so you end up with$\frac{ d }{ dx }(\tan3x-\csc4x)=3\sec^2(3x)+4\cot(4x)\csc(4x)$

16. Twis7ed

^Do you understand that?

17. Hoa

it's the best

18. onegirl

yes, so i dont have to multiply the derivatives of 3x and 4x into the whole problem?

19. onegirl

yes i understood what you wrote/

20. Twis7ed

I'm not sure, what is the entire question?

21. onegirl

Okay so I found the derivative of that and my teacher told me to multiply 3x and 4x into it here is how i did it hold on

22. onegirl

d/dx (tan(3)x - csc 4x = tan(3) - csc 4

23. onegirl

i think i understnad where i went wrong now after seeing what you showed

24. Twis7ed

ALright, just try to remember that when you have a trig function you usually use the chain rule with the function and then the function inside of it and it should be easy :)

25. onegirl

okay thanks