I've already had some good discussion with Fat32 in this question yesterday.
Today I'm confused again. The author of Statistical digital signal processing and modeling M.h. Hayes and Fat32 both stated that Padé can approximate p+q+1 samples. Then I found this exercise
Do I count wrong or are there 5 samples used for the approximation? q+p+1 should be $2+3+1=6$ and therefor 6 perfectly approximated samples. Okay I've calculated it. Due to the periodicity the sixth sample is correct too. But what if the vector would be e.g. 10 at $x[5]$ (sixth sample)?
To solve for the a's I'd then have 3 equations for the vector $[1, a_1, a_2]^T$ which is impossible to solve. Where do I make the mistake?