Number 5 and 6. Explanations pls

5. [-/1 Points] DETAILS MY NOTES PRACTICE ANOTHER A variable star is one whose brightness alternately increases and decreases, which can be modeled using a sine function. For one such star, the time between periods of maximum brightness is 3.9 days, the average brightness of the star is 4.3, and its brightness varies by +0.35 (so the difference between maximum brightness and minimum brightness is 0.7). Find a sine function that models the brightness of the star as a function of time ( in days), t. Assume that at t = 0 the brightness of the star is 4.3 and that it is increasing. f (t ) = 6. [-/4 Points] DETAILS SCALCET9 1.3.055. MY NOTES PRACTICE ANOTHER Use the table to evaluate each expression. m N H X f(x) H m N 9 (x) LO H m (a) Alg(4) ) (b) g(f (2) ) (c) (f . 9) (1) (d) (g . f)(1)