diff --git a/balloon/lib/math.nas b/balloon/lib/math.nas
index e8092d4..77a3b99 100644
--- a/balloon/lib/math.nas
+++ b/balloon/lib/math.nas
@@ -1,4 +1,6 @@
 var pi=3.14159265358979;
+var ln_2=0.69314718055994530942;
+var ln_10=2.30258509299404568402;
 
 var abs=func(__x)
 {
@@ -96,4 +98,47 @@ var cos=func(__x)
 var tan=func(__x)
 {
     return sin(__x)/cos(__x);
+};
+
+var sqrt=func(__x)
+{
+    if(__x>100){return 10*sqrt(__x/100);}
+    var t=__x/8+0.5+2*__x/(4+__x);
+    var c=10;
+    while(c>0)
+    {
+        t=(t+__x/t)/2;
+        c-=1;
+    }
+    return t;
+};
+
+var __balloon_lib_asin_asr=func(__x,__y)
+{
+    var __mid=(__x+__y)/2;
+    if(abs(__y-__x)<=0.01){return (1/sqrt(1-__x*__x)+4/sqrt(1-__mid*__mid)+1/sqrt(1-__y*__y))*(__y-__x)/6;}
+    return __balloon_lib_asin_asr(__x,__mid)+__balloon_lib_asin_asr(__mid,__y);
+};
+
+var asin=func(__x)
+{
+    if(abs(__x)>1){return -1;}
+    var fl=1;
+    if(__x<0){fl=-fl;__x=-__x;}
+    if(abs(__x-1)<0.001){return pi/2;}
+    return fl*__balloon_lib_asin_asr(0,__x);
+};
+
+var acos=func(__x)
+{
+    if(abs(__x)>1) {return -1;}
+    return pi/2-asin(__x);
+};
+
+var atan=func(__x)
+{
+    if(__x<0){return -atan(-__x);}
+    if(__x>1){return pi/2-atan(1/__x);}
+    if(__x>0.001){return 2*atan((sqrt(1+__x*__x)-1)/__x);}
+    return __x*(1-__x*__x*(1/3+__x*__x*(1/5-__x*__x*(1/7+__x*__x/9))));
 };
\ No newline at end of file