When teaching this subject in the past I found that all students were puzzled by the fact that the figures show V1 and VR decreasing with increasing temperature, while V2 does the opposite.
As I said in an earlier post, I have never seen a definitive explanation of this curiosity, but had surmised that it was due to the decreasing value of 1.1 Vmca. Having looked more closely at the figures I can see that this is not the case.
Can you suggest a (not too complex) explanation?