Using the provided database answer the questions using relational algebra

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 1. Course(s) for which only one section was created in the Spring 2009 semester. 2. Grades given to student(s). 3. ID(s) of instructor(s) who is are advisor(s). 4. Course section(s) instructor(s) Srinivasan taught in the Fall 2009 semester. We are only interested in course id and sec id here, cause course section is uniquely identified by the values for course_id, sec_id, semester, year and values for attributes semester, year we already know (these are 'Fall, 2009 respectively)