Write an equivalent expression in relational algebra for the following sql query?
select p. name, c. name
from professor p, course c, taught t
where p. id = t. profid and t. semester = 's2002'
and t. crscode = c. crscode

How do you take a green screen out of the video while editing?

Write a program that prints the day number of the year, given the date in the form month-day-year. for example, if the input is 1-1-2006, the day number is 1; if the input is 12-25-2006, the day number is 359. the program should check for a leap year. a year is a leap year if it is divisible by 4, but not divisible by 100. for example, 1992 and 2008 are divisible by 4, but not by 100. a year that is divisible by 100 is a leap year if it is also divisible by 400. for example, 1600 and 2000 are divisible by 400. however, 1800 is not a leap year because 1800 is not divisible by 400.

Asample of 200 rom computer chips was selected on each of 30 consecutive days, and the number of nonconforming chips on each day was as follows: 8, 19, 27, 17, 38, 18, 4, 27, 9, 22, 30, 17, 14, 23, 15, 14, 12, 20, 13, 18, 14, 20, 9, 27, 30, 13, 10, 19, 12, 26. construct a p chart and examine it for any out-of-control points. (round your answers to four decimal places.)