34. Electricity The combined electrical resistance R of two resistors R₁ and R₂, connected in parallel, is given by 1 1 + R R₁ R₂ where R, R₁, and R₂ are measured in ohms. R, and R, are increasing at rates of 1 and 1.5 ohms per second, respectively. At what rate is R changing when R₁ = 50 ohms and R, = 75 ohms?