# What is there in the derivation of the Taylor/Maclaurin series for #sin(x)# that determines if the series assumes #x# is radians or degrees?

##### 2 Answers

If the angle is not measured in radians, then the differentiation rule

In establishing (proving) that rule we use

That is also not true if

And that's because proving

If the central angle

With

If

We have:

You could also just say that the idea of the MacLaurin series for

When you do

But this is just a quick check. The actual proof might not be like this; I don't remember how it actually went.