Question: If two resistors R1 and R2, ohms are connected in parallel in an electric circuit

to make an R-ohm resister, the value of R can be found from the equation

1 1 1

___ = ___ + ____

R R1 R2

If R1 is decreasing at the rate of 3 ohm/sec and R2 is increasing at a rate of 5 ohm/sec, at what rate is R changing when R1 = 60 ohms and R2 = 40 ohms.