What is the y-intercept

For f(x)=2x+1 and g(x)= x^2 -7, find (f•g)(x)

The average number of vehicles waiting in line to enter a parking lot can be modeled by the function f left parenthesis x right x squared over 2 left parenthesis 1 minus x right parenthesis endfraction , where x is a number between 0 and 1 known as the traffic intensity. find the rate of change of the number of vehicles waiting with respect to the traffic intensity for the intensities (a) xequals0.3 and (b) xequals0.6.

The function f(x) = 14,600(1.1)* represents the population of a town x years after it was established. what was the original population of the town?