I'm working on understanding an example problem in order to do a homework
problem, but it does not explain things well.
It asks to sketch the voltage as a funtion of time at x = 100 meters

V(x,t) = 100 cos (10^6t - 0.0628x) volts

where t is in seconds and x is in meters along the line.

The solution the book shows is a cosine wave with a peak of 100. I don't understand how they got this, does anyone know?

V(x,t) = 100 cos (10^6t - 0.0628x) volts

where t is in seconds and x is in meters along the line.

The solution the book shows is a cosine wave with a peak of 100. I don't understand how they got this, does anyone know?