A Cepheid variable star is a star whose brightness alternately increases and decreases. Suppose that Cephei Joe is a star for which the interval between times of maximum brightness is 6.6 days. Its average brightness is 2.6 and the brightness changes by /-0.6. Using this data, we can construct a mathematical model for the brightness of Cephei Joe at time t, where t is measured in days:

(a) Find the rate of change of the brightness after t days.
(b) Find the rate of increase after one day.

Respuesta :

Answer:

a) Rate of brightness after t days = B(t) = 2.6 + 0.6sin(2×3.142 t /6.6)

b) 0.57

Step-by-step explanation:

Given

Number of days=6,6 days

Average brightness =2.6

B(t)= 2.6 + 0.6 sin (2× 3.142t/6.6)

b) B(1day) = 0.6 ×(2×3.142/6.6)cos (2×3.142/6.6)

B(1 day) = 0.6 × (6.248/6.6)cos 0.952

B(1 day) =0.6 × 0.952 ×0.9999

B(1day) = 0.5711

= 0.57