Hello, everyone. Tom from everystepcalculus.com and everystepphysics.com. Curl problem using the PQR System of Notation, for variables. So let’s do it. Index 8 to get to my menu. We’re going to scroll down to Curl. You can hold that button down or you can just press it each time to go down. Here’s P Q R, Curl PQR. We’re going to choose that. Do a Curl problem. Choose PQR again. That’s what you’re doing. That’s how it’s notated. Cartesian up here and vector notation here with the arrows on the ends. We’re going to use these up here. Alpha Y times Z squared. Alpha, you have to press alpha before you enter anything into these entry lines here. Alpha X times Y. Alpha Y squared times Z. I show you what you’ve entered, you can change it if you want. I say it’s okay. This is the tough part do the cross product of partial fractions, here. That’s tough. You gotta remember that and what to do. That’s why I programmed it so you never make a mistake on it. It’s mindless stuff so why ponder it. Put it in a program and use it. Here’s the computations of that. I J K is Cartesian. I is X, J is Y, and K is Z axis. And here’s the answer here. Okay. Now we can do several things but let’s compute it at a point. Number 3. Compute the curl at a point. Let’s enter Alpha 1, Alpha 2, Alpha 3. Again, I show you what you’ve entered in case you made a mistake. It puts the x and the y and the z values into this formula. The quotation marks are there, you should use parentheses where you see quotations. Because your’e substituting 3 for x or Z, in the case Z squared plus 4 times Z times 2 which is Y plus Y. And the answer is 17. Pretty neat, huh? everystepcalculus.com. Goto my site, subscribe to see more videos. Have a good one.