Number & Algebra

HL only. 2 investigations, ~55 marks total, 1 hour. Each problem builds 8-12 parts from compute → conjecture → prove. Calculator allowed.

~30 min per investigation. Don't get stuck on one part — move to the next; later parts may give you clues for earlier ones.

Almost every part: M1 (method shown) + A1 (correct value/expression) + R1 (justification or conclusion). The R1 marks compound — losing them kills your top band.

$z_{n+1} = f(z_n)$ — fixed points satisfy $z = f(z)$; long-term behaviour ⇒ attracting (sequence converges to it) or repelling.