Using the provided database answer the questions using relational algebra

A) Course(s) with prereqisite(s) from other departments. We are interested in course id(s), title(s) and dept name(s) of a course with its prerequisites course_id(s), title(s) and dept_name(s).

B) Course section(s) what student(s) enrolled in but no one taught. We are interested in course_id(s), sec_id(s), semester(s), year(s) here.

C) Classroom(s) with the smallest capacity. We are interested in building and room number here.

D) Student(s) whose name(s) are the same as name(s) of some instructor(s). We are interested in ID(s) and name(s) of this\those student(s).

classroom building string room_number number capacity number department dept_name string building string budget number course course_id string title string dept_name string credits number instructor ID number name string dept_name string salary number section course_id string sec_id number semester string year number building string room_number number time_slot_id string teaches ID number course_id string sec_id number semester string year number student ID number name string dept_name string tot_cred number takes ID number course_id string sec_id number semester string year number grade string advisor s_id number i_id number time_slot time_slot_id string day string start_hr number start_min number end_hr number end_min number prereq course_id string prereq_id string