diff --git a/src/ikarus.boot b/src/ikarus.boot
index 09f6fc0..ae08c7c 100644
Binary files a/src/ikarus.boot and b/src/ikarus.boot differ
diff --git a/src/ikarus.numerics.ss b/src/ikarus.numerics.ss
index 1127c9a..1024f15 100644
--- a/src/ikarus.numerics.ss
+++ b/src/ikarus.numerics.ss
@@ -142,7 +142,7 @@
           abs
           exact->inexact inexact floor ceiling round log fl=? fl<? fl<=? fl>?
           fl>=? fl+ fl- fl* fl/ flsqrt flmin flzero? flnegative?
-          sin cos atan sqrt
+          sin cos tan asin acos atan sqrt
           flround flmax random)
   (import 
     (ikarus system $fx)
@@ -160,7 +160,7 @@
             exact-integer-sqrt min max abs
             fl=? fl<? fl<=? fl>? fl>=? fl+ fl- fl* fl/ flsqrt flmin
             flzero? flnegative?
-            sin cos atan sqrt
+            sin cos tan asin acos atan sqrt
             flround flmax random))
 
 ;    (foreign-call "ikrt_fixnum_to_flonum" x))
@@ -1550,6 +1550,27 @@
         [(fixnum? x) (foreign-call "ikrt_fx_cos" x)]
         [else (error 'cos "unsupported ~s" x)])))
 
+  (define tan
+    (lambda (x)
+      (cond
+        [(flonum? x) (foreign-call "ikrt_fl_tan" x)]
+        [(fixnum? x) (foreign-call "ikrt_fx_tan" x)]
+        [else (error 'tan "unsupported ~s" x)])))
+
+  (define asin
+    (lambda (x)
+      (cond
+        [(flonum? x) (foreign-call "ikrt_fl_asin" x)]
+        [(fixnum? x) (foreign-call "ikrt_fx_asin" x)]
+        [else (error 'asin "unsupported ~s" x)])))
+
+  (define acos
+    (lambda (x)
+      (cond
+        [(flonum? x) (foreign-call "ikrt_fl_acos" x)]
+        [(fixnum? x) (foreign-call "ikrt_fx_acos" x)]
+        [else (error 'acos "unsupported ~s" x)])))
+
   (define atan
     (lambda (x)
       (cond
diff --git a/src/makefile.ss b/src/makefile.ss
index 59ed446..c9d5607 100755
--- a/src/makefile.ss
+++ b/src/makefile.ss
@@ -455,8 +455,11 @@
     [expt                    i r]
     [sin                     i r]
     [cos                     i r]
-    [sqrt                    i r]
+    [tan                     i r]
+    [asin                    i r]
+    [acos                    i r]
     [atan                    i r]
+    [sqrt                    i r]
     [number?                 i r]
     [bignum?                 i]
     [ratnum?                 i]
diff --git a/src/todo-r6rs.ss b/src/todo-r6rs.ss
index db70023..76e8398 100755
--- a/src/todo-r6rs.ss
+++ b/src/todo-r6rs.ss
@@ -79,11 +79,11 @@
     [*                                          C ba se]
     [/                                          C ba se]
     [abs                                        C ba se]
-    [acos                                       S ba se]
+    [acos                                       C ba se]
     [angle                                      D ba se]
     [append                                     C ba se]
     [apply                                      C ba se]
-    [asin                                       S ba se]
+    [asin                                       C ba se]
     [assert                                     C ba]
     [assertion-violation                        S ba]
     [atan                                       C ba se]
@@ -219,7 +219,7 @@
     [symbol->string                             C ba se]
     [symbol=?                                   C ba]
     [symbol?                                    C ba se]
-    [tan                                        S ba se]
+    [tan                                        C ba se]
     [truncate                                   S ba se]
     [values                                     C ba se]
     [vector                                     C ba se]