The demand function for a certain brand of backpacks is where is the unit price in dollars and is the quantity (in hundreds) demanded per month. Find the elasticity of demand, and determine the range of prices corresponding to inelastic, unitary, and elastic demand. If the unit price is increased slightly from , will the revenue increase or decrease?

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.

Yea they are simplyfiy the ratios