Add tests for power using recursion algorithm (#4335)

src/main/java/com/thealgorithms/maths/PowerUsingRecursion.java

@@ -0,0 +1,20 @@
+package com.thealgorithms.maths;
+
+/**
+ * calculate Power using Recursion
+ * @author Bama Charan Chhandogi (https://github.com/BamaCharanChhandogi)
+ */
+
+public class PowerUsingRecursion {
+
+    public static double power(double base, int exponent) {
+        // Base case: anything raised to the power of 0 is 1
+        if (exponent == 0) {
+            return 1;
+        }
+
+        // Recursive case: base ^ exponent = base * base ^ (exponent - 1)
+        // Recurse with a smaller exponent and multiply with base
+        return base * power(base, exponent - 1);
+    }
+}