Trigonometry
Which of the following statements correctly describes the procedure for obtaining the graph of y = -13 + 8 cos x from the graph of y = 8 cos x?
Translate the graph of y = 8 cos x by 13 units downward.
Translate the graph of y = 8 cos x by 13 units to the left.
Reflect the graph of y = 8 cos x across the x-axis and stretch it vertically by a factor of 13.
Reflect the graph of y = 8 cos x across the x-axis and compress it vertically by a factor of 13.