Half angle formula assistance

[daliberataaa!]

Homework Statement

given that sin theta = 3/5, 0 < theta < pi/2 find sin theta/2

Homework Equations

http://www.intmath.com/Analytic-trigonometry/sinalphaon2.gif [Broken]

The Attempt at a Solution

I appologize that I don't know how to use all the symbols on a keyboard (square roots, etc)
But I have so far gotten it to :

square root of 1-3/5 all over 2. I have a sample of this same problem in my book, but they don't explain the next step. Suddenly this problem from here just turns into square root of 1/5...can someone please explain how they got to there?

Thank you all.

 

[daliberataaa!]

ok i feel like the biggest idiot in the world...i got it.

I blame sleep deprivation...haha.