Name the move

Recognition speed training. Read the trigger, name the technique in under 10 seconds. Free and unlimited: no AI involved, just reps.

1. Quadratic with root conditions (both positive, etc.)

2. Interval like -3 <= x <= 1 asked as absolute value

3. Subtracting same-base powers

4. Every k hours starting at time t (pills, shifts)

5. Every-pair-once (handshakes, games); xC2 = N

6. Four-term polynomial

7. Without-replacement probability given only a ratio

8. Sum of same-base powers