1. Consider the following collection of relation schemes: ( IT FUNDAMENTAL OF DATA BASES)

professor(profname, deptname) department(deptname, building) committee(profname, committee_name)

Write Relational Query Expression to do the following:

a. Find all the committee name where Professor Ahmed is a member

b. Find all the professor names in the CS department

2. Consider the following collection of relation schemes:

instructor (ID, name, dept_name, salary)

teaches (ID, course id, sec id, semester, year)

Using the above relations, write an equivalent relational algebra expression for the following:

_name (s_{instructor.ID =teaches.ID} (s_{dept_name =Physics} (instructor teaches)))

please be sure it is correct answer