Saving, I think

Java-Assignment-004.iml

@@ -5,6 +5,7 @@
     <content url="file://$MODULE_DIR$">
       <sourceFolder url="file://$MODULE_DIR$/src" isTestSource="false" />
     </content>
+    <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />
   </component>
 </module>

src/Multadd.java

@@ -0,0 +1,35 @@
+public class Multadd {
+
+    public static double multadd(double a, double b, double c) {
+        return a * b + c;
+    }
+
+    public static void main(String[] args) {
+        // This next line isn't necessary, but I'm given to understand from googling it, that adding this as a constant helps with clarity and reliability.
+        final double PI = Math.PI;
+        double result1 = multadd(2.0, 4.0, 6.0);
+        System.out.println("multadd(2.0, 4.0, 6.0) = " + result1);
+        double result2 = multadd(1.5, 3.14, -2.7);
+        System.out.println("multadd(1.5, 3.14, -2.7) = " + result2);
+        double result3 = multadd(0.0, 10.0, 0.0);
+        System.out.println("multadd(0.0, 10.0, 0.0) = " + result3);
+
+        double sinPi4 = Math.sin(PI / 4);
+        double cosPi4 = Math.cos(PI / 4);
+        double log10_10 = Math.log10(10);
+        double log10_20 = Math.log10(20);
+        double formula1 = multadd(sinPi4, cosPi4 / 2, 0);
+        System.out.println("sin(pi/4) + cos(pi/4)/2 = " + formula1);
+        double formula2 = multadd(log10_10, log10_20, 0);
+        System.out.println("log10(10) + log10(20) = " + formula2);
+        double x = 1.23;
+        double expSumResult = expSum(x);
+        System.out.println("expSum(" + x + ") = " + expSumResult);
+    }
+
+    public static double expSum(double x) {
+        double expX = Math.exp(-x);
+        double sqrtTerm = Math.sqrt(1 - expX);
+        return multadd(x, expX, sqrtTerm);
+    }
+}