# Homework Help: Differentiation of Trigonometric functions

1. Dec 31, 2008

### MaxManus

1. The problem statement, all variables and given/known data
Let y = tan2(3x-2)
Find dy/dx

The solution is:
2*tan(3x-2)*sec(3x-2)*3
= 6*tan(3x-2)*sec2(3x-2)

Why is it not:
6*tan(3x-2)*sec(3x-2)

I am thinking:
y = (tan(3x-2))2
take the power 2 down,multiply with the parentes multiply with the defferentiated parentes

Edit: Happy new year

2. Dec 31, 2008

### tiny-tim

happy new year!

Hi MaxManus! Happy new year!

(what are parentes? do you mean "parenthesis"?)

y = (thing)2,

so y' = 2(thing)(thing') …

in this case, the thing is a tan, and tan' = sec2

3. Dec 31, 2008

### jgens

What do you think d(tan(u))/dx is equivalent to?

Edit: tiny-tim beat me to it.

4. Dec 31, 2008

### tiny-tim

happy new year!

na na na na-na! :tongue:

hic!

happy new year!

5. Dec 31, 2008

### jgens

Happy new year! :)

6. Dec 31, 2008

### MaxManus

Thanks tiny-tim and jgens.
Yes, I ment parenthesis, but I could not spell it.

7. Dec 31, 2008

### HallsofIvy

Hitting the champagne a little early?