Tips to today's HW

Q6
Volume of a cuboid = L x B x H
In the question, can you see that x+y=3 (as 2x+2y=6)

For the base of the box, one side is y, the other side is 2-2x.

Hence, for the cuboid,
you have
L : y or (3-x) because x+y=3
B : 2-2x
H : x

Hence use L x B x H to find vol of box.

For this topic, instead of dealing with y=function of x all the time, we solve problems relating volume of prisms, areas etc.

Method is similar to finding turning (stationary points) of curves.
Tomorrow I will still spend some time on this topic.