added recognition of zero exponent to instantly return 1 to reduce room for errors

src/main/py/calculations_with_roots.py

@@ -8,4 +8,6 @@ def multiplyRoots(first_number, second_number):
 def sqrt_power(base, exponent):
     if base < 0:
         return -1
+    if exponent == 0:
+        return 1
     return potentiate(sqrt(base), exponent)