Find the area enclosed by the x-axis and the curve x = 4 + et, y = t − t2.

Find where the curve intersects the x-axis; this happens when y = 0:

y = t - t ² = 0   →   t (1 - t ) = 0   →   t = 0, t = 1

Then the area of the bounded region is

(you can compute the integral by parts)

a.   since the profit made in 2012 is equal to the profit made in 2014, the profit is symmetric about the line y = 120,000.

step-by-step explanation: