$2\mathrm{.}1\mathrm{.}3$ There are several software programs available today which can plot graphs.

Choose one software and use it to answer the investigation in $2\mathrm{.}1.$

Cut and paste your graphs in your answer book where necessary.

Deduce the effect of $p.$

Clearly indicate the name of the software and explain how it works.

Comment on the accessibility of the software.

$(20)$