posted by sh .
I need help to start this problem please,
A company can sell 4500 pairs of sunglases monthly when the price is $5. When the price of a pair of sunglasses is increased by 10%, the demand drops to 4250 pairs a month. Assume that the demand equation is linear.
Find the demand equation
Assume the demand equation is linear.
We have two known points:
P1(5,4500), and P2(5.50,4250)
To fit a straight line between two known points, we can apply the two-point form of line, namely,
The equation seems long, but its symmetry makes it very easy to memorize.
Substitute x1=5,y1=4500,x2=5.5,y2=4250, we get