a)
df
(
x, h
) = 3
x
2
h
,
(
x, h
) = 3
xh
+
h
2
; b)
df
(
x, h
) = (6
x
-
5)
h
,
(
x, h
) = 3
h
; c)
df
(
x, h
) =
,
(
x, h
) =
-
; d)
df
(
x, h
) =
-
,
(
x, h
) =
.