A company manufactures a new type of solar panel. The rate of change of energy output, in kilowatt-hours per day, of a prototype panel is modelled by the function
R(t)=12e−0.2t+4cos(12πt)
where
t is the time in days since the panel was first activated, for
t≥0.
The total energy output
E(t), in kilowatt-hours, satisfies
E(t)=∫R(t)dt and
E(0)=0.