Hi
T = 420 - 350 (3.2)^-.1m |where m represents the number of minutes after the oven is turned on
and T represents the temperature of the oven in degrees Fahrenheit.
T = 420 - 350 (3.2)^-.1m
(T-420)/-350 = 3.2^.1m
log[(T-420)/-350]/log(3.2) = -.1m
T = 320
log[(-100)/-350]/log(3.2) = -.1m
log .2857/log(3.2) = -.544/.5 = -.1m
-1.08 = -.1m
m = 10.8 min, time it takes to reach a temperature of 320F