diff --git a/hocdecl.h b/hocdecl.h
index de6857f..7a2b0b0 100644
--- a/hocdecl.h
+++ b/hocdecl.h
@@ -36,7 +36,7 @@ extern  double in2mm(double d);
 extern  double mm2in(double d);
 extern  double po2kg(double d);
 extern  double kg2po(double d);
-
+extern  double nthroot(double d , double n);
 /*
 **      functions in FUNCT.C
 */
diff --git a/math.c b/math.c
index 9127db1..b7aeaa1 100644
--- a/math.c
+++ b/math.c
@@ -87,3 +87,7 @@ double kg2po(double d)
 {
 	return (d * 1000) / 453.592;
 }
+/* nth root of d*/
+double nthroot(double d , double n){
+ return Pow(d,1.0/n);
+}