In this test you are to develop unit tests for a scientific calculator. a$)$ Write a total of $9$ tests, organized into $3$ sets. b$)$ Each test should target one functional element of the prgram $($you cannot use $+,-,/,$ and $*)$ c$)$ Write the code that allows the program to pass your tests. d$)$Explain your approach in each test. what was your strategy here? e$)$ Capture screenshot or console logs of code before and after it passed the tests, shwoing the output of the unit testing library. Shorten out to most important part where it lists number of tests passed and failed.