MA 1310
posted by Mike .
What is the amplitude, period and phase shift for y = 1/4 cos (3x +7)? Thank you, please show work.

rewrite it in the more general form as
y = (1/4) cos 3(x + 7/3)
compared to y = a cos k(Ø + p)
the amplitude is 1/4
the period is 2π/3
the phase shift is 7/3 to the left
for your equation in the original form a common mistake would be to state that the sphase shift is 7.
Note the step I took to avoid that error.