Posted by Lee on .
The number of people taking the bus at price p dollars per ticket is given by x=5000(5p)^1/2.
For what value of P is the demand unitary?

Calculus 
drwls,
"Unitary demand" occurs where p*x = constant, which also implies that
dp/p = dx/x,
which is another way of saying
dx/dp = x/p
In your case
dx/dp = 5000*(1/2)/(5p)^1/2
= 2500/(5p)^1/2
= x/p = 5000*(5p)^1/2*(1/p)
1 = 2*(5p)/p
p = 10  2p
p = $3.33