In the attached notebook I want the function y11[x_] to display only up to t = d = 0.68, and not all the way up to t= 1.0. I have tried all kinds of variations of the Plot statement, but to no avail.
I wonder whether there might be a typo in your answer. In my end, at least, inserting [0.68,0.68] as the plot interval for y11 produces an error, and no wonder since this gives a plot range of zero.
May be I was not clear enough in my explanation! So… The plotting interval of the first Plot[] function is [0,1], the second - [d, 1]. I mean that if in the first interval you put [0,d], you obtain that the intersection of intervals is [d,d], or [0.68, 0.68]. I set for the both Plot[] functions the same interval [0,d], and the issue disappeared.
I still cannot get the plot to work. - The final plot should range as 0 <= t <= 1.0. Substituting as I understand you suggest does not produce a plot from zero to 1.0, with the first function ending at t = 0.68, and the second function beginning at t = 0.68.
Is it possible that you could apply your corrections to my notebook, and attaching the corrected notebook to your answer? (I include a copy of my notebook as an attachment, for your convenience).