Final answer:
The range when y equals cosine x is -1 less than or equal to y less than or equal to 1 because the values of cosine x are bound between -1 and 1.
Step-by-step explanation:
The range when y equals cosine x is -1 less than or equal to y less than or equal to 1 because the values of cosine x are bound between -1 and 1.
For any angle x, the value of cosine x represents the y-coordinate of a point on the unit circle. Since the y-coordinate of a point on the unit circle ranges from -1 to 1, the range of y when y equals cosine x is -1 less than or equal to y less than or equal to 1.
For example, when x is 0, cosine x is 1 and when x is π, cosine x is -1.