4 Find the intervals in which the function f given by
3
13
( )
,
0
f x
x
x
x
=
+
≠
 is
(i) increasing
(ii) decreasing Rationalised 2023-24
 MATHEMATICS
184
5 Find the maximum area of an isosceles triangle inscribed in the ellipse 
2
2
2
2
1
x
y
a
b
+
=
with its vertex at one end of the major axis