Question

what are the amplitude, period, mid-line, minimum, and maximum of y=2cos(4x)

Answer 1

y = acos(bx+c)=====> a is amp, b is freq, c is your phase shift

Answer 2

so we now the amplitude to be highest or lowest a wave will go
the period is divide as the distance it takes for one cycle to complete, thus if a circles is 2pi, then 2pi/b gives you your period and im not sure what a mid line is... one sec

Answer 3

ok and the mid line is just an indication of whether the graph has change with respect to its origin. so if it was sin x there would be no change thus the mid line is 0, if it where sin(x) +1 the mid line would be raised one because we shifted the graph up one. so the mid line is then 1