Question given: newtons law of cooling is given by

(Θ=theta)

Θ=Θoe^-kt

where the excess of tempreature at 0 deg = Θo deg and the time T is Θ deg.

given that Θo=15 deg and K=-0.02 find the time when the rate of change of tempture is 1 deg

my work

1=15e^-0.02XT

i assume u must use log to rearence the forumla in oder to get a value then differentiate it to find the rate of change of T.

is what iv done so far correct?