3 ms·

It is actually linear. a,b,c,d are the unknowns and x1 and x2 are the inputs. A bit confusing since normally x1,x2 denote the unknowns.

• zmk_ 13y ago
  Not if you are doing econometrics/statistics.
• tomrod 13y ago
  Unless you like econometrics: then X are data, betas and gammas and sigmas are unknown (oh my!). Jargon is fun, unless I want to communicate across fields :/.
  • omn123 13y ago
    Well today I learned. I never knew that. Stupid mathematics and its inconsistent notation.
    • tomrod 13y ago
      It makes sense when you look at historical development, but there is no reason to learn separate notations now without learning all sides :).