Exercise 2.4.1 a),f),h) Product(maker,model,type) PC(model,speed,ram,hd,price) Laptop(model,speed,ram,hd,screen,price) Printer(model,color,type,price) Write expressions of relational algebra to answer the following queries.For the data of Figs2.20 and 2.21,show the result of your query a)what PC models have a speed of at least 3.00? t Mode (o(speed >=3.00)(PC)) Result: 1005 1006 1013 f)Find those hard-disk sizes that occur in two or more PC's. R1=Ppel (PC) R2=Ppe2(PC) R3=R1 0-JOIN (pe1.hd=pe2.hd and pel.model pe2.model)R2 R4=元pc1hd(R3) Result: 250 80 160 h)Find those manufacturers of at least two different computers(PC's or laptops)with speeds of at least 2.8 R1=Tmodel.speed(PC)modelspeed (Laptop) R2=TMakermodel ((speed>=28(R1)natural JOIN Product)) R3=p T(maker2,model2)(R2) R4=R2 theta JOIN maker=maker2 AND modelmodel2(R3) Answer(maker)=Maker (R4) Result: B,E Exercise 2.5.1 b) Product(maker,model,type) PC(model,speed,ram,hd,rd,price) Laptop(model,speed,ram,hd,screen,price) Printer(model,color,type,price) Write your constraints either as containments or by equating an expression to the empty set.ForExercise 2.4.1 a), f), h) Product (maker, model, type) PC(model, speed, ram, hd, price) Laptop(model,speed,ram,hd,screen,price) Printer(model,color,type,price) Write expressions of relational algebra to answer the following queries. For the data of Figs2.20 and 2.21, show the result of your query. a) what PC models have a speed of at least 3.00？  Model ( (speed >=3.00) (PC)) Result: 1005 1006 1013 f) Find those hard-disk sizes that occur in two or more PC’s. R1 = pc1 (PC) R2 = pc2 (PC) R3 = R1 -JOIN (pc1.hd = pc2.hd and pc1.model <>pc2.model) R2 R4 =  pc1.hd (R3) Result: 250 80 160 h) Find those manufacturers of at least two different computers (PC’s or laptops) with speeds of at least 2.8 R1 = model,speed (PC)   model,speed (Laptop) R2 = Maker,model ( (Speed >= 2.8 (R1) natural JOIN Product)) R3 =  T(maker2,model2)(R2) R4 = R2 theta JOIN maker=maker2 AND model <> model2 (R3) Answer(maker) = Maker (R4) Result: B,E Exercise 2.5.1 b) Product (maker, model, type) PC(model, speed,ram,hd,rd,price) Laptop(model,speed,ram,hd,screen,price) Printer(model,color,type,price) Write your constraints either as containments or by equating an expression to the empty set. For