Based on the curve of Jensen Ackles’ lovely spinal column in the photo above (from Supernatural 1x04, “Phantom Traveler”), the equation to Jensen Ackles’ ass (i.e. the Ackles Ass Equation) is y=-(sin(x^(1.7/6)+4)+(1/x))+10.
To graph the Ackles Ass Equation, input the equation above into a graphing calculator (since I’m betting not many of you want to graph it by hand—if you want to graph it at all). I’m using a TI-83 Plus, but any graphing calculator should work just fine.
In the ‘window’ options, set Xmin to 1 and Xmax to 10 or 11 so that you can narrow down your domain and so you don’t get the infinite curves that come with a sine function. Make sure Ymax is set to something higher than 10. Now, view your graph, and Jensen Ackles’ ass should be waiting for you. Sort of. ;) This is how my curve looks.
If you have any issues graphing the curve, make sure you’re in radian mode. You might also want to browse the comments here to see if your problems/questions have already been addressed. Otherwise, feel free to drop a message in my ask, and I’ll do my best to help you.