I need to show that x^2 is continuous on its domain using the epsilon-delta definition. So far, I've started with |(x^2) - (c^2)|< E, which is the same as |x+c||x-c|< E. However, I'm not quite how to get from here to |x-c|< D, where D is delta (which I'm pretty sure is supposed to depend on epsilon and c).