Implement the <math.h> sqrt() function

src/math/exp.c

@@ -0,0 +1,19 @@
+/* This is free and unencumbered software released into the public domain. */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+/**
+ * @date   2017-10-09
+ * @author Samuel Sarle
+ * @see    http://libc11.org/math/exp.html
+ */
+
+double
+exp(double x) {
+  x =  1 + (x / 1048576);
+  for (int i = 0; i < 20; i++) {
+    x *= x;
+  }
+}

src/math/fabs.c

@@ -12,5 +12,5 @@
 
 double
 fabs(const double x) {
-  return (x < 0) ? -x: x;
+  return (x < 0) ? -x : x;
 }

src/math/ldexp.c

@@ -4,13 +4,14 @@
 #include <config.h>
 #endif
 
+#include <math.h>     //For pow()
+
 /**
  * @date   2017-10-04
  * @author Samuel Sarle
  * @see    http://libc11.org/math/ldexp.html
  */
 
-#include <math.h>     //For pow()
 
 double
 ldexp(const double x, const long long y) {

src/math/sqrt.c

@@ -0,0 +1,28 @@
+/* This is free and unencumbered software released into the public domain. */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+/**
+ * @date   2017-10-05
+ * @author Samuel Sarle
+ * @see    http://libc11.org/math/sqrt.html
+ */
+
+double
+sqrt(const double x) {
+  if (x <= 0) {
+    return 0;
+  }
+
+  int i = 0; 
+  while( (i * i) <= x ) {
+    i++;
+  }
+  i--; 
+  double z = x - i * i;        //Bakhshali approximation
+  double y = z / (2 * i);         
+  double w = i + y; 
+  return w - (y * y) / (2 * w);
+}