00:01
All right, hello! in this question we're given these two parametric equations, and we're told that time equals one.
00:04
We want to evaluate the following.
00:06
I'm not told what the following are, but we can only evaluate so many things, which is why i'm going to do this question.
00:11
Let's go ahead and evaluate x at one.
00:13
Well, i'm just going to have one third times one cubed minus five times one.
00:17
That is going to be negative fourteen thirds.
00:21
Let's also evaluate y at one.
00:23
That's going to be one minus one third times one cubed, which is going to be two thirds.
00:28
And then i'm guessing what the question asks is let's go ahead and evaluate dy dx evaluated at time equals one.
00:36
In order to do that, we need to figure out what dy dx is.
00:39
Well, we know dy dx is going to be dy dt divided by dx dt.
00:45
You can think of it as it's technically a chain rule thing, but you can think of the dt's as cancelling.
00:50
Just don't tell your math teacher that's how you're thinking about it...
