00:01
Okay, so in this chapter, we've been talking about different variations of different variables.
00:04
So if something varies directly with something, that means as it increases, the other variable will increase as well.
00:10
And if something varies inversely as the one variable increases, the other will decrease.
00:15
So given a constant k, i have a couple different variables here.
00:19
Let's say the strength of a wood beam s varies jointly.
00:23
Okay, jointly means they vary directly.
00:25
So as the strength increases, then the width of the beam will also increase.
00:30
So it's going to be divided so they both increase.
00:35
And the square of the thickness of the beam.
00:37
Okay, square implies to the square.
00:40
The thickness, let's call that t.
00:42
Jointly means these two terms will be multiplied together and they both are direct variation.
00:48
And the strength varies inversely.
00:50
Okay, so this item will decrease, so it'll be multiplied here as the length of the beam...