diff --git a/src/funktion.c b/src/funktion.c
index 35dcbca..b17068c 100644
--- a/src/funktion.c
+++ b/src/funktion.c
@@ -145,3 +145,9 @@ float Vaddx3(float x3, float z3){
     double result = x3 + z3;
     return result;
 }
+float Vsubstract(float x1, float z1) {
+    float X1;
+    X1 = x1 - z1;
+    printf("(%f: \n", X1);
+    return X1;
+}
diff --git a/src/funktion.h b/src/funktion.h
index 519e24a..6cda55b 100644
--- a/src/funktion.h
+++ b/src/funktion.h
@@ -28,5 +28,6 @@ double Vlength(float x1, float x2, float x3);
 float Vadd(float x1, float z1);
 float Vaddx2(float x2, float z2);
 float Vaddx3(float x3, float z3);
+float Vsubstract(float x1, float z1);
 
 #endif
diff --git a/src/main.c b/src/main.c
index 8c47725..f9c1171 100644
--- a/src/main.c
+++ b/src/main.c
@@ -120,4 +120,10 @@ int main()
     x3 = getValue('X');
     z3 = getValue('z');
     Vaddx3(x3,z3);
+
+    printf("x eingeben");
+    x1 = getValue('x');
+    printf("a eingeben");
+    z1 = getValue('z');
+    Vsubstract(x1, z1);
 }