diff --git a/fx_s2308_double.c b/fx_s2308_double.c
index d5f5b475b96a9b21c7808488f4fd355b2b691135..7e56d7284d6935d3e3663b8c10970f424611349d 100644
--- a/fx_s2308_double.c
+++ b/fx_s2308_double.c
@@ -4,16 +4,16 @@
 #define PI 3.1415926535897
 #define TO_RADIAN(a) (a*(PI/180))
 
-fx_s2308 fx_sine(fx_s2308 a){
+fx_s2308 fx_s2308_double_sine(fx_s2308 a){
 	double f_a=FX_TO_DOUBLE(a);
 	f_a=TO_RADIAN(f_a);
 	return DOUBLE_TO_FX(sin(f_a));
 }
-fx_s2308 fx_sqrt(fx_s2308 a){
+fx_s2308 fx_s2308_double_sqrt(fx_s2308 a){
 	double f_a=FX_TO_DOUBLE(a);
 	return DOUBLE_TO_FX(sqrt(f_a));
 }
-fx_s2308 fx_pow(fx_s2308 a, double n){
+fx_s2308 fx_s2308_double_pow(fx_s2308 a, double n){
 	double f_a=FX_TO_DOUBLE(a);
 	return DOUBLE_TO_FX(pow(f_a,n));
 }
diff --git a/fx_s2308_double.h b/fx_s2308_double.h
index 237238460d3ebad233e829d25f6e9a9ded98637a..cf07897cc857f870d116cb7c7f63df5a78e4311d 100644
--- a/fx_s2308_double.h
+++ b/fx_s2308_double.h
@@ -12,7 +12,7 @@ typedef double fx_s2308;
 #define PI 3.141592
 #define FX_PI (INT_TO_FX(PI))
 
-fx_s2308 fx_sine(fx_s2308 a);
-fx_s2308 fx_sqrt(fx_s2308 a);
-fx_s2308 fx_pow(fx_s2308 a, double n);
+fx_s2308 fx_s2308_double_sine(fx_s2308 a);
+fx_s2308 fx_s2308_double_sqrt(fx_s2308 a);
+fx_s2308 fx_s2308_double_pow(fx_s2308 a, double n);
 
diff --git a/test.c b/test.c
index 8fdf999aa16921aeec9159edc557021cb1fa73a6..e6690fc384c0b88a0640a32106c0599b7c103cec 100644
--- a/test.c
+++ b/test.c
@@ -10,19 +10,19 @@ int main() {
 	printf("===sine test===\n");
 	double a1=30.0;
 	fx_s2308 f_a1=DOUBLE_TO_FX(a1);
-	fx_s2308 sine_a1=fx_sine(f_a1);
+	fx_s2308 sine_a1=fx_s2308_double_sine(f_a1);
 	printf("%lf %lf %lf\n",a1,f_a1,FX_TO_DOUBLE(sine_a1));
 
 	printf("===sqrt test===\n");
 	double a2=100.0;
 	fx_s2308 f_a2=DOUBLE_TO_FX(a2);
-	fx_s2308 sqrt_a2=fx_sqrt(f_a2);
+	fx_s2308 sqrt_a2=fx_s2308_double_sqrt(f_a2);
 	printf("%lf %lf %lf\n",a2,f_a2,FX_TO_DOUBLE(sqrt_a2));
 	
 	printf("===power test===\n");
 	double a3=64.0;
 	fx_s2308 f_a3=DOUBLE_TO_FX(a3);
-	fx_s2308 pow_a3=fx_pow(f_a3,2.0);
+	fx_s2308 pow_a3=fx_s2308_double_pow(f_a3,2.0);
 	printf("%lf %lf %lf\n",a3,f_a3,FX_TO_DOUBLE(pow_a3));