Why would central be $10$ when we're trying to find $t=200?$

Central is an array to store the value of Altitude's derivative for a particular time. For $t=200,$

central $[10]$ is used to store the corresponding value $($the index i starts from $0,$ and central$[10]$ is

the ${11}^{th}$ element in the array$).$ Therefore, we are printing central$[10].$

Another way to think about it: the array Central $i$ is not a function of $t,$ while it is the function

of $i.i$ is related to $t$ by $t=h^{**}i.$ When we print $i^{**}h,$ central$[$i$],$ we are listing the value of $t,$ and the

derivative at this value.