Domain: Set of all real numbers
Range:
where y is a real number
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The domain is the set of real numbers because there are no restrictions on what to plug in for x. There are no gaps, holes, jumps, or asymptotes. The graph continues on in both directions stretching to both infinities (this is indicated by the arrows on the curve ends)
The range is the set of y values between -1 and 1 because this is the set of y outputs. The largest y can get is +1 or just 1. The smallest y can get is -1. The value of y can be any number in between as there are no gaps.