Write an expression of relational algebra to answer

a ) Find the ID and name of those students who have completed the course with code CS-A2220 with grade 4 or 5, but have not completed the course with code CS-A1120 at all.

b ) Find the code and name of all courses with 5 credits which have been completed by any student whose program is TIK with grade 3.

c ) Find the ID and name of those students who have started in Year 2020 and have completed both course with code CS-A2220 and course with code CS-A1120, both with grade 5.

d )Find those students who have completed both the course with code CS-A2220 and the course with code CS-A1120 with the same grade. The result relation should contain the ID and name of the student as well as the student's grade.

In relational algebra expression Please,thank you

Movies(title, year, length, genre, studioName, prodno) Moviestar (name, address, gender, birthdate) starsin(movieTitle, movieyear, starName) MovieExec (name, address, certno)