Chapter 5: Exercises with Solutions

Chapter 5Quadratic Functionsy100 f(x)=2(x+5/2) 2 −121/2x=−5/2(−8,0) (3,0)x20(−5,−48)(−5/2,−121/2)(0,−48)To find the domain of f, mentally project every point of the graph onto the x-axis, asshown on the left below. This covers the entire x-axis, so the domain= (−∞, ∞). Tofind the range, mentally project every point of the graph onto the y-axis, as shown onthe right below. The shaded interval on the y-axis is range= [−121/2, ∞).y100 f(x)=2(x+5/2) 2 −121/2y100 f(x)=2(x+5/2) 2 −121/2x20x20(−5/2,−121/2)61. To find the solutions of ax 2 +bx+c = 0, note where the graph of f(x) = ax 2 +bx+ccrosses the x-axis (see figure below). Thus, the solutions are −2 and 3.y5x5Version: Fall 2007