Derivation of f(x)=xcos(sen(x)) – 1

[schmitt]

Hi Could someone help me derivating this function:

f(x)=xcos(sen(x)) – 1
f'(x)= ?
f''(x)= ?

Thank you.

 

[I like Serena]

Hi Could someone help me derivating this function:

f(x)=xcos(sen(x)) – 1
f'(x)= ?
f''(x)= ?

Thank you.

What kind of function is sen(x)?
Or did you mean sec(x)?

 

[DeadOriginal]

If that sen(x) is indeed a sec(x) then just use the product rule between x and cos(sec(x)). The -1 becomes 0. When you get the new function derive it again and you'll have f''(x).

You might be asking for the answer in which case I won't be giving you because you'll never learn it yourself.

Woops. Just realized that mistake I made. That was embarrassing.

 

[schmitt]

What kind of function is sen(x)?
Or did you mean sec(x)?

sorry, its "sin(x)"

 

[Mark44]

You are going to need to use the product rule and the chain rule, in that order.

BTW, there is no such word as "derivating" in English, and I doubt that it is a word in any other language. To find the derivative of a function, we differentiate the function - we don't "derivate" it or "derive" it.

Starting with ax² + bx + c = 0, I can derive the Quadratic Formula, but this has nothing to do with differentiation.

 

[schmitt]

Got it solved already, sorry for the bad english.
Topic can be deleted.

 

[Mark44]

We don't delete the topics so that other people with similar questions can learn from them.