I'm having trouble with this problem from a review sheet of mine.
Consider the price-demand equation x=f(p)=(144-2p)^(1/2) , 0>p>72.
a) Calculate the elasticity of demand at p 20, 40 and 60. Describe each case as
elastic or inelastic. For what value of p is demand unit elastic?
b) Express total revenue as a function of price p and find the value of p which
maximizes total revenue.
c) Explain, for the given price-demand equation, the connection between elasticity of
demand and the increasing/decreasing behaviour of the total revenue function
depending on price p !
What I'm really struggling with is converting the equation to the correct one for a). The answer given by the review is E=(p)/(144-2p). But the closest I've come was E=1/(144-2p)
Any help is great!