I'm trying to create a function that graphs a capital "B" So it's not really a function, it has multiple y values for some x values, but I'm achieving that by using "±" signs when appropriate. My problem, however is the vertical line. I thought for a long time how to come up with a equation that could graph a vertical line in one particular x value, but be a relatively normal function throughout the rest of its domain. I decided to use a fourier series, as shown below: In case you can't see the picture: y = sum_(k = 1)^∞ ((sin(2*pi*(2k-1))*x)/(2k-1)) You may or may not know that that graphs a square wave, (which has vertical lines) both according to wikipedia and a short python program I made, but according to wolframalpha, it does not. So, do you know whether or not this plots what I think it does? Also, to manipulate the function to make it a vertical line at x = 0, but y = 0 when x ≠ 0, I multiplied it by this function of x: In case you can't see the picture: floor(e^(-abs(x))) which is equal to 0 when x ≠ 0, but equals 1 when x = 0. The question I have about this is, because it would zero out the function at every x value except for exactly one, would a vertical line created by the former function at that exact point be unaffected? Thank you, and sorry if this is a little wordy, or posted in the wrong place.