(func f(x) sin x)
;;
(func f(x) (sin x))
(roots f (.3 1.8) .0001)
(roots f 2 .01)
(roots f 2)
(roots f 2 1e-3) ;; find a pretty good (not a great) root.
 
(func f(x) ln x)
(func f(x) (ln x))
(func f(x) ln (x))

(roots f (.3 1.8) .0001) ;; root is 1, for both