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 6 A tank with rectangular base and rectangular sides, open at the top is to be
constructed so that its depth is 2 m and volume is 8 m3 If building of tank costs
Rs 70 per sq metres for the base and Rs 45 per square metre for sides