When an electric current passes through two resistors with resistance [math] and [math], connected in parallel, the combined resistance, [math], can be calculated from the equation [math] where [math], [math] , and [math] are positive. Assume that [math] is constant.

Find [math]:
[math]

Is [math] and increasing or decreasing function of [math]?
(Enter increasing, decreasing, neither, or both (write both if there are values of [math] for which [math] is increasing, and other values for which it is decreasing; enter neither if this is a constant function.)

If we consider the interval [math], where does [math] take on its global maximum and minimum values?
maximum: [math]
minimum: [math]
(Enter none if there is no global maximum or minimum for this function.)