Calculus
posted by Abigail .
An electrical circuit switches instantaneously from a 2 volt battery to a 20 volt battery 3 seconds after being turned on. Sketch on a sheet of paper a graph the battery voltage against time. Then fill in the formulas below for the function represented by your graph.
For t < _____ , V(t) = _____
For t ¡Ý _____, V(t) = _____
At what point or points is your function discontinuous?
t = ______

The change occurred at t=3 seconds.
So at t<3 seconds, V(t)=2 volts
at t>3 seconds, V(t)=? volts
Discontinuity is at t=? 
t < 8 V(t) =5
T>8 V(t) =18
t=8 
if two resistors with resistances r1 and r2 ohms are connected in parallel in an electric circuit to make an rohms resistor , the value of r can be found from the equation 1/r=1/r1+1/r2. if r1 is decreasing at the rate of 1 ohm/sec , and r2 is increasing at the rate of 0.5 ohm/sec , at what rate is r changing when r1=75 ohms and r2=50 ohms

An electrical circuit switches instantaneously from a 3 volt battery to a 23 volt battery 7 seconds after being turned on. Sketch on a sheet of paper a graph the battery voltage against time. Then fill in the formulas below for the function represented by your graph.