## Calculus 8th Edition

$B(t)=4.0+0.35 sin[\frac{2π}{5.4} t]$
The average brightness is 4.0. The amplitude of the graph is 0.35. The period is 5.4 days. We can use these values to write a function that models the brightness: $B(t)=4.0+0.35 sin[\frac{2π}{5.4} t]$