fixed grammatical errors

Author: ChrisO345

maths/maclaurin_sin.py

@@ -23,7 +23,7 @@ def maclaurin_sin(theta: float, accuracy: int = 30) -> float:
     >>> maclaurin_sin("10")
     Traceback (most recent call last):
     ...
-    ValueError: maclaurin_sin() requires a int or float for theta
+    ValueError: maclaurin_sin() requires either an int or float for theta
     >>> maclaurin_sin(10, -30)
     Traceback (most recent call last):
     ...
@@ -39,10 +39,14 @@ def maclaurin_sin(theta: float, accuracy: int = 30) -> float:
     """
 
     if not isinstance(theta, (int, float)):
-        raise ValueError("maclaurin_sin() requires a int or float for theta")
+        raise ValueError(
+            "maclaurin_sin() requires either an int or float for theta"
+        )
 
     if not isinstance(accuracy, int) or accuracy <= 0:
-        raise ValueError("maclaurin_sin() requires a positive int for accuracy")
+        raise ValueError(
+            "maclaurin_sin() requires a positive int for accuracy"
+        )
 
     theta = float(theta)