Multiply both sides by x. We get 8 is equal to 2x squared. Divide both sides by 2. You get 4 is equal to x squared. And if we were just purely solving this equation, we would get x is equal to plus or minus 2. Now we're saying that the function is only defined over this interval, so negative 2 isn't part of its domain, so we're only going to focus on x is equal to 2. This right over here is definitely a critical number.