A variable has the density curve with equation y = 1 − x/2 for 0 < x < 2, and y = 0 otherwise.

a. Graph the density curve of this variable.

b. Show that the area under this density curve to the left of any number x between 0 and 2 equals x − x 2/4. Hint: First find the area to the right of x and then apply Property 2 of Key Fact