AREAS OF PLANE REGIONS USING DEFINITE INTEGRALS 1. Find the area in the first quadrant bounded by f(x)=4x-x^2 and the X-axis. 2. Find the area of the plane region bounded by y = 3x + 1, x = 1, x = 3,and the x-axis. 10 y = 3x + 1 2 3 3. Find the area of the plane region bounded above by y = 1 -| x- 1 | and below by the x-axis. 1=1- |x - 1|