Question
Find the area of the region bounded by the line y = 3 x + 2, the x-axis and the ordinates x = - 1 and x = 1.
Solution
The equation of given line is
y = 3 x + 2 ...(1)
Consider the lines
x = -1 ...(2)
and x = 1 ...(3)
Line (1) meets x-axis where y = 0
putting y = 0 in (1), we get,
line (1) meets x-axis in 
Let line (1) meet lines (2) and (3) in B and D respectively. From B, draw BC ⊥ x-axis and from D, draw DE ⊥ x-axis.
Required area = Area of region ACBA + area of region ADEA
