let center of smaller circle is P ....coordinates of P will be (r,r) ..........
r is the radius of smaller circle...
let point of contact of both circles if q then , pq = r (from the diagram)
if o is origin then
op = (r2+r2) = r(root2) (by distance formula)
oq = op + pq = r(root2) + r = r(root2+1)
oq is also radius of bigger circle so
R = r(root2+1)
r = 1 (given) so
R = (root2+1)