Graphs of Functions - Exercise 1

For the function f(x) = x⁴ - 4x², solve x⁴ - 4x² = 0 in order to find the x-intercepts, justifying steps in finding these intercepts. Find points on each side of each x-intercept, placing values in the table below.  Graph this function on your graphing calculator. Be able to explain why f(x) is even, show the points you generated, and show a sketch of the graph.  Is f(x) an even function? Why or why not?