finished

src/App.java

 public class App {
     public static void main(String[] args) throws Exception {
-        Complex a = new Complex(4.2, 5.7);
+
+        // First test
+        /* Complex a = new Complex(4.2, 5.7);
         a.imag();
         a.real();
+        System.out.println(a.imag);
+        System.out.println(a.real);
+        System.out.println(a.real());
+        System.out.println(a.imag()); -> correct */ 
+
+        // Second test
+        /* Complex a = new Complex(9.6, 11.5);
+        System.out.println(a.magnitude()); -> correct */
+
+        // Third test
+        /* Complex a = new Complex(9.6, 11.5);
+        System.out.println(a.argument()); -> correct */
+
+        // Fourth test
+        /* Complex a = new Complex(1.2, 3.4);
+        System.out.println(a.toString());
+        Complex b = new Complex(1.2, 0.0);
+        System.out.println(b.toString());
+        Complex c = new Complex(0.0, 9.3);
+        System.out.println(c.toString());
+        Complex d = new Complex(1.2, -3.4);
+        System.out.println(d.toString()); -> correct */
+
+        // Fifth test
+        Complex a = new Complex(6.6, 12.9);
+        Complex b = new Complex(13.1, 13.5);
+        Complex c = a.add(b);
+        System.out.println(c.real());
+        System.out.println(c.imag()); 
     }
 }

src/Complex.java

@@ -2,6 +2,7 @@ public class Complex {
 
   public double real;
   public double imag;
+  public double d;
 
   public Complex()
   {
@@ -13,7 +14,7 @@ public class Complex {
   {
     this.real = r;
     this.imag = i;
-    //double d = Math.atan2(i,r);
+    this.d = Math.atan2(i,r);
   }
 
   public double imag()
@@ -33,7 +34,7 @@ public class Complex {
 
   public double argument()
   {
-    return Math.atan2(this.imag, this.real);
+    return d;
   }
 
   public String toString()