The marketing research department for a computer company

Question

The marketing research department for a computer company used a large city to test market the firm s new laptop. The department found that the relationship between price p (dollars per unit) and demand x (units sold per week) was given approximately by

p=1,296 - 0.12x² 0<=x<=80

So, weekly revenue can be approximated by

R(x)=xp=1,296x - 0.12x³ 0<=x<=80

Graph the revenue function R.