Gradient of a Function

Let's talk about the gradient of a function. In order to talk about the gradient, so I have to first talk about the gradient del operator. Also, it's an upside-down triangle. So you can see over here how we define, so you get like del delx in the i direction, which is the unit vector in x, right, del dely, del delz in the y and z directions respectively, okay? So basically, then you add the function to it, right, f. And this can be a function of x, y, z. Let me write this down; I'll be right back. Okay, I'm back. So you can see whenever I see these three dot dots, I just put whatever the function is. So it's fairly straightforward. I'll give you a quick example. Let's say that this f x y z, this is simple example, is x square minus y cube. Obviously, it's a function, right? So you need to do it yourself, but at the end, I'll get this 2x i minus 3y square j. Make sure you can get this, and you can see this a vector, right? It has components in the x direction and the y direction.