Also handle elliptic curve, fix some grammar error

Author: user202729

src/sage/matrix/matrix_space.py

@@ -957,7 +957,7 @@ def characteristic(self):
 
     def is_exact(self):
         """
-        Test whether elements of this matrix space is exact.
+        Test whether elements of this matrix space are represented exactly.
 
         OUTPUT:
 

src/sage/modules/free_module.py

@@ -1010,7 +1010,7 @@ def is_sparse(self):
 
     def is_exact(self):
         """
-        Test whether elements of this module is exact.
+        Test whether elements of this module are represented exactly.
 
         OUTPUT:
 

src/sage/schemes/elliptic_curves/ell_generic.py

@@ -1076,6 +1076,19 @@ def is_on_curve(self, x, y):
         a = self.ainvs()
         return y**2 + a[0]*x*y + a[2]*y == x**3 + a[1]*x**2 + a[3]*x + a[4]
 
+    def is_exact(self):
+        """
+        Test whether elements of this elliptic curve are represented exactly.
+
+        EXAMPLES::
+
+            sage: EllipticCurve(QQ, [1, 2]).is_exact()
+            True
+            sage: EllipticCurve(RR, [1, 2]).is_exact()
+            False
+        """
+        return self.__base_ring.is_exact()
+
     def a_invariants(self):
         r"""
         The `a`-invariants of this elliptic curve, as a tuple.

src/sage/structure/parent.pyx

@@ -2863,7 +2863,7 @@ cdef class Parent(sage.structure.category_object.CategoryObject):
 
     cpdef bint is_exact(self) except -2:
         """
-        Test whether elements of this parent is exact.
+        Test whether elements of this parent are represented exactly.
 
         .. NOTE::