The graph shows how last a voltage signal rises in a elecommunications etreuit. The basis is the
vorage in volts and taxis is the time in seconds.
The function shown is v(t) = 10(1 - 4^-t)
Show why v(0) = 0.
How long does it take for the voltage to rise to 5
volts? Explain your answer using the function
and the laws of exponents.