Suppose a hot cup of coffee is left on a kitchen counter. If the temperature in °F after t hours is given by
F(t) = 85 + 125(0.65t),
find the instantaneous rate of change of the coffee's temperature after an hour and a half. (Round your answer to two decimal places.)
can you please explain how to do. thanks

Question

Suppose a hot cup of coffee is left on a kitchen counter. If the temperature in °F after t hours is given by 
F(t) = 85 + 125(0.65t),
 find the instantaneous rate of change of the coffee's temperature after an hour and a half. (Round your answer to two decimal places.)
can you please explain how to do. thanks

anonymous · Answer

take the derivative and plug in $1.5$ for $t$

anonymous · Answer

will do

anonymous · Answer

give me a second

anonymous · Answer

nope
i do get derrivative but no correct answer

anonymous · Answer

the derivative is 
$$125\ln(.64)(.64)^t$$[

anonymous · Answer

compute 
$$125\ln(.64)(.64)^{1.5}$$should do it