How Do You Calculate the Derivative of √sin(x)?

[domyy]

Homework Statement

y = √sinx

The Attempt at a Solution

y' = [(sinx)^1/2]'
y' = 1/2 (sinx)^-1/2 (sinx)'
y' = 1/2 cosx (sinx)^-1/2

However book says the answer should be:

1/2 cotx (√sinx)

 

[Coelum]

Hint: what is the definition of cotan(x)?

 

[Dick]

Your answer is right. The book's answer is also right. cot(x)=cos(x)/sin(x). Try to convince yourself they are both right.

 

[domyy]

1/tanx ?

 

[voko]

And what is tan in terms of cos and sin?