root(16)=+- 4, me assume yu want +4
the rest av that stuf...me assume its spozed tu be:
-root(15) / [2*root(2)]
root(15)=3.8729833462074168852....
root(2)=1.41421 35623 73095 04880 16887 24209 69807 85696 7187....
2*root(2)=2.82842712474619009760337744841939615713....
root(15)/[2*root(20)]=1.36930639376291528365