The following equations will graph a penis in the 1st quadrant of your calculator. There are six equations required to make a complete picture, and they are labeled below. Feel free to modify the equations to give your penis a more customized feel! That was the oddest juxtaposition of words that I have ever written, pretty sure.
Make sure you follow the standard order of operations.
I used a Texas Instruments TI-89 with a window from -10 to 10 on both axes.
y = (x-2)^2/(sqrt(sqrt(14)-(x-2)^2)/9999+1)
y = sqrt(6.25-(x-(4.5+sqrt(3.5)))^2)/9999+3.5
y = sqrt(4-(x-(4+sqrt(3.5)))^2)/9999+6
y = (-2.5x+2.5*(7+sqrt(3.5))+3.5)/(sqrt(.5-(x-(6.5+sqrt(3.5)))^2)/9999+1)
y = 6*(x-9)^2/(sqrt(.1-(x-9.35)^2)/9999+1)+3
y = -(x-8.3)^2/(sqrt(1-(x-8.5)^2)/9999+1)+7
If graphed correctly, you should have a penis that comfortably resides in the 1st quadrant.
P.S. I really do recommend the TI-89 titanium. If your professor allows it, it will make your life a breeze.