MATHEMATICS · Subjective · AP · Calculus AB · Limits and Continuity · Limits and Continuity
Problem
The temperature T, in degrees Celsius, of water in a laboratory tank was recorded every 6 hours:
Time t (h): 0 6 12 18 24
Temperature T(t) (°C): 18 23 17 22 18
Assuming T is continuous on 0≤t≤24, determine the least number of distinct times in this 24-hour period at which the temperature must have been exactly 20 °C. State that number and justify briefly.