Addition of Secant Method (#876)

* Add files via upload

* Update secant_method.py

* Remove unused import

* Remove unused import

arithmetic_analysis/secant_method.py

@@ -0,0 +1,28 @@
+# Implementing Secant method in Python
+# Author: dimgrichr
+
+
+from math import exp
+
+
+def f(x):
+    """
+    >>> f(5)
+    39.98652410600183
+    """
+    return 8 * x - 2 * exp(-x)
+
+
+def SecantMethod(lower_bound, upper_bound, repeats):
+    """
+    >>> SecantMethod(1, 3, 2)
+    0.2139409276214589
+    """
+    x0 = lower_bound
+    x1 = upper_bound
+    for i in range(0, repeats):
+        x0, x1 = x1, x1 - (f(x1) * (x1 - x0)) / (f(x1) - f(x0))
+    return x1
+
+
+print(f"The solution is: {SecantMethod(1, 3, 2)}")