# Domain of a function (analytical method)

• Mar 27th 2011, 12:50 PM
AlanaSan
Domain of a function (analytical method)
Hello,

I have this problem :
Find the Domain of g(x) = sinX

I can find the answer by graphic analyse :
Domain of g(x) =Reals {[2K π, 2K π + π] : K belongs a Woles Numbers}

But I dont know do it by analitical method.
Can someone show me the methode to resolve this exercice without graphic helps?

Thanks
• Mar 27th 2011, 06:33 PM
tonio
Quote:

Originally Posted by AlanaSan
Hello,

I have this problem :
Find the Domain of g(x) = sinX

I can find the answer by graphic analyse :
Domain of g(x) =Reals {[2K π, 2K π + π] : K belongs a Woles Numbers}

But I dont know do it by analitical method.
Can someone show me the methode to resolve this exercice without graphic helps?

Thanks

The ony way I can see, and the easiest one, is by knowing:

1) that the real square root function has to have a non-negative argument, and

2) knowing the trigonometric functions, in this case the sine function.

And then you get at once the domain you got...

Tonio