2. Find the open intervals on which f(x) = 1/(x^2) is increasing or decreasing.

Answer 1

Look at the graph of f(x) = 1/x². It looks like this:

For increasing functions, the y-values go up (increase) as you move left to right and for decreasing functions, the y-values go down (decrease) as you move left to right. So can you see that f(x) = 1/x² increases on (-∞, 0) and decreases on (0, ∞)?