1 files changed, 37 insertions, 0 deletions
diff --git a/math.c b/math.c
index 2cac83e938..86c889dca9 100644
--- a/math.c
+++ b/math.c
@@ -57,6 +57,39 @@ math_tan(obj, x)
 }
 
 static VALUE
+math_acos(obj, x)
+    VALUE obj, x;
+{
+    Need_Float(x);
+    /*
+    if (RFLOAT(x)->value < -1.0 || RFLOAT(x)->value > 1.0)
+	rb_raise(rb_eArgError, "Out of range (-1..1)");
+    */
+    return rb_float_new(acos(RFLOAT(x)->value));
+}
+
+static VALUE
+math_asin(obj, x)
+    VALUE obj, x;
+{
+    Need_Float(x);
+    /*
+    if (RFLOAT(x)->value < -1.0 || RFLOAT(x)->value > 1.0)
+	rb_raise(rb_eArgError, "Out of range (-1..1)");
+    */
+    return rb_float_new(asin(RFLOAT(x)->value));
+}
+
+static VALUE
+math_atan(obj, x)
+    VALUE obj, x;
+{
+    Need_Float(x);
+    
+    return rb_float_new(atan(RFLOAT(x)->value));
+}
+
+static VALUE
 math_exp(obj, x)
     VALUE obj, x;
 {
@@ -140,6 +173,10 @@ Init_Math()
     rb_define_module_function(rb_mMath, "sin", math_sin, 1);
     rb_define_module_function(rb_mMath, "tan", math_tan, 1);
 
+    rb_define_module_function(rb_mMath, "acos", math_acos, 1);
+    rb_define_module_function(rb_mMath, "asin", math_asin, 1);
+    rb_define_module_function(rb_mMath, "atan", math_atan, 1);
+
     rb_define_module_function(rb_mMath, "exp", math_exp, 1);
     rb_define_module_function(rb_mMath, "log", math_log, 1);
     rb_define_module_function(rb_mMath, "log10", math_log10, 1);