but not Mach which is a function of pressure height
.. and CAS. Hence we need speed and height to figure out Mach.
M = (5((qc/ps+1)^0.286-1))^0.5
is a typical sort of equation one finds in the textbooks.
I wouldn't fuss too much about the hieroglyphs .. the important bit is that
M = an equation involving CAS and Hp.