[填空题]
The most popular mobile phqn 13tg8 x1bjeone plans in 2019 from a major mof,: hilyqmjrs7 n.em 8; ,si7jbile service provider in Australia are summarised,hql rsfj. e j:iy,is7m ;n8m7 in the table below.
1.The total monthly cost, C, in AUD, of the Optimal Data Plan can be modelled as a piecewise linear function of the amount of data, d, in GB, used. Determine the model.
2.Find down the total monthly cost of the Optimal Data Plan if:
(1)8 GB of data is used; AUD
(2)12 GB of data is used. C = AUD
3.Determine how many GB of data is used when the Optimal Data Plan becomes more expensive than the Massive Data Plan.
Daniela is using the Optimal Data Plan and is thinking of changing it to the MassiveMassive Data Plan. It is the evening of December 7, 2019 and she has already used 3.5 GB of data so far. Assume that her data usage continues at the same constant rate during December and the next year.d =
4.Estimate Daniela's data usage in December. GB
5.Hence explain why Daniela should change her plan.
6.Find the amount of money Daniela will save each month in 2020 if she changes her Optimal Data Plan to the Massive Data Plan. AUD
