Derivative of 5 tan 3x

Question

Derivative of  5 tan 3x

amtran_bus · Answer

Is it 5 sec^2 x?

amtran_bus · Answer

I know tan = sec^2 u * u' 
for chain rule

geerky42 · Answer

what happened to 3?

myininaya · Answer

yep you found the derivative of 5 tan(x)

amtran_bus · Answer

I'm sorry. I'm confused. Can someone walk me through this? Here is what I know

derivative tan = sec^2 u * u' with chain rule

myininaya · Answer

derivative of tan(u) w.r.t. x is sec^2(u)  * u'

what is your u here?

amtran_bus · Answer

I would say 3x

myininaya · Answer

yep yep plug in

amtran_bus · Answer

sec^2 (3x) *3.  

Or should I say 5 sec^2 (3x) *3
that would be 15 sec^2 3x

myininaya · Answer

is Qui yes in french ?

myininaya · Answer

Oui

amtran_bus · Answer

Thanks for your help! I am self teaching myself calc. All I have is a larson book and soln manual and open study!

geerky42 · Answer

Have you tried using Khan Academy

amtran_bus · Answer

I do watch it occasionally. I also forgot about a guy named Professor Leonard on youtube that has cal 1, 2, and 3 videos. He is a prof and records lectures.

geerky42 · Answer

Khan Academy has plenty of calculus videos. It also provides interactive problems. https://www.khanacademy.org/math/calculus-home

geerky42 · Answer

I personally think it's great tool for self-learning.