a$.$ In the code what do the array xx and the array yy represent?

b$.$ Explain what this line do:

A $=$ np$.$array$([$ np$.$ones$($ xx$.$shape $),$ xx $]).$T

Note: Writing this creates the matrix A is not enough. Something like this creates the matrix A such

as the first column is $...$ and the second column is $...,$ each row represents $...$ is needed

c$.$ Explain what this line do:

b $=$ np$.$array$([$ np$.$log$($yy$)$ np$.$log$($xx$)]).$T

d$.$ Explain what this line do: x $=$ np$.$linalg.lstsq$($A$,$b$,$rcond$=$None$)[0]$

e$.$ Explain what this line do: yyy$[$i$]=$ exp$($x$[0])$ xxx$[$i$]$ exp$($ x$[1]$ xxx$[$i$])$

f$.$ We find that the model is

c$($t$)=7\mathrm{.}12$ t e$0\mathrm{.}18$t

$.$

What is c$($t$)?$ What is t$?$

g$.$ Do you think we have a good fit? Is this a good model?

h$.$ Describe biologically$/$physically what is happening? Why is the curve rapidly increasing, and then slowly

decreasing with time?

i$.$ Visually, answer the question: Suppose that the therapeutic range for the drug is $415$ ng$/$ml$.$ Estimate

the time interval the drug concentration stays within therapeutic levels. $($Visually means look at the

graph and guess an interval.$)$