Write relational algebra queries for the two specifications below using the relations also defined below:
a. retrieve the names of customers who have ordered parts costing less than $150.00.
b. retrieve the names of customers and the partname of orders with a qty greater than 10.
parts(pno, pname, qoh, price, olevel)
customers(cno, cname, street, zip, phone)
employees(eno, ename, zip, hdate)
zip_codes(zip, city, state)
orders(ono, cno, eno, received, shipped)
odetails(ono, pno, qty)
where qoh stands for quantity on hand and olevel stands for (re)order level. the p, c, e and o single letter prefixes for attributes refer to the parts, customers, employees and orders relations, respectively. the other attribute names are self-explanatory.

In a heat transfer course, we can derive the equation for the temperature distribution in a flat rectangular plate. in this example, we will look at a plate at steadystate with three sides being held at t1, and one side held at t2. the temperature for any location on the plate, t(x,y), can be calculated by where create a function (prob3_5) that will take inputs of vectors x and y in feet, scalar n, scalars l and w in feet and scalars t1 and t2 in degrees fahrenheit. it will output a matrix t which is the temperature of each x and y locations. t will have the number of columns equal to the number of elements in x and rows equal to the number of elements in y. though this can be done without loops (perhaps more efficiently), your program must use a nested loop.

This isn't about school but every time it tells me to watch an ad to unlock the answer to a question it prompts a survey and it just keeps loading. so i haven't been able to get answers for my tests in like a week.

How is a wan different than a lan? both connect computers, but only wan users don’t need the same operating system. both are peer-to-peer networks, but only a wan requires networking hardware. both network computers, but only a wan can cover larger geographical ranges. both connect computers to the internet, but only wan connects to the cloud.