diff --git a/Mex/a622.cpp b/Mex/a622.cpp
new file mode 100644
index 0000000..8d73b67
--- /dev/null
+++ b/Mex/a622.cpp
@@ -0,0 +1,56 @@
+#include "mex.h" 
+#include "matrix.h"
+#include "stdlib.h"
+
+
+
+void mexFunction(int nlhs, mxArray *plhs[], 			// Output  
+				 int nrhs, const mxArray *prhs[]) 		// Input  
+{
+	char *func_Name;
+	func_Name = mxArrayToString(prhs[0]);
+	
+	double a = *mxGetPr(prhs[1]);
+	double x1= *mxGetPr(prhs[2]);
+	double precision = *mxGetPr(prhs[3]);
+	double A=0;
+	
+	int fak = 1;
+	
+	double ya = 0;
+	
+	
+//trapz
+	mxArray *func_Input[1];
+	mxArray *func_Outputs[1]; 
+
+	for(int i = 0; a < x1; a += precision)
+	{
+		func_Input[0] = mxCreateDoubleScalar(a);
+		mexCallMATLAB(1, func_Outputs , 1 , func_Input , func_Name);
+		ya = *mxGetPr(func_Outputs[0]);
+		A += fak*ya;
+		
+		
+		if(i%2)			
+			fak=2;
+		else
+			fak=4;
+	}
+	
+	func_Input[0] = mxCreateDoubleScalar(a);
+	mexCallMATLAB(1, func_Outputs , 1 , func_Input , func_Name);
+	ya = *mxGetPr(func_Outputs[0]);
+		
+	A += ya;
+	A = A*precision/3;
+
+// Output
+	plhs[0] = mxCreateDoubleScalar(A);
+	
+//free allocated memory
+	mxDestroyArray(func_Input[0]);
+	mxDestroyArray(func_Outputs[0]);
+		 
+ return;
+}
\ No newline at end of file
diff --git a/Mex/a622.m b/Mex/a622.m
new file mode 100644
index 0000000..92f3765
--- /dev/null
+++ b/Mex/a622.m
@@ -0,0 +1,7 @@
+% function accepts 1 string and 3 doubles 
+%		a622("function", interval_start, interval_end, precision)
+%
+%		a622 implements trapz (integral)
+%
+%exp.:	a622("sin",0,pi/2,0.000001)
+%		ans = 1.0000
\ No newline at end of file
diff --git a/SCE/SCE/INTEGRAL.cpp b/SCE/SCE/INTEGRAL.cpp
index ec57fde..195b238 100644
--- a/SCE/SCE/INTEGRAL.cpp
+++ b/SCE/SCE/INTEGRAL.cpp
@@ -29,7 +29,7 @@ long double INTEGRAL::trapz(long double x0, long double x1, long double precisio
 
 long double INTEGRAL::quad(/*long double (* funk)(long double), */long double x0, long double x1, long double precision)
 {
-	long double A = 0, a = x0, b = a + precision;
+	long double A = 0, a = x0;
 	int fak = 1;
 
 	for (int i = 0; a < x1; a += precision, i++)