How do you find the domain & range for #y=5cos(1/2)(x-(pi/4) +5#?

1 Answer
Jun 7, 2016

The domain of a sinusodial function is all the real numbers. The range, however, is determined by two things: the amplitude and the vertical displacement.

Explanation:

In function #f(x) = acosb(x - c) + d#, the amplitude is given by #|a|# and the vertical displacement is given by #d#.

Therefore, your function has a vertical displacement of #5# and an amplitude of #5#. A vertical displacement means you moved the graph up by #d# units from the x axis. The amplitude is the distance between the center line (#y = 5# in this case) and the maximum/minimum points of the function. Thus, the maximum points will be at #(x, 10) and (x, 0)#. The can be summarized as #"minimum in y"<= y <= "maximum in y "#, or in the case of this function, #0 <= y <= 10#.

In conclusion, the domain of #y = 5cos((1/2)(x - pi/4)) + 5 # is #x="all the real numbers" # and the range is #0 <= y<= 10#.

Hopefully this helps!