To determine which trigonometric function has a range that does not include 0.4, let's analyze the ranges of the given functions:
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y = cos x: The range of the cosine function is from -1 to 1, so it does include 0.4.
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y = cot x: The cotangent function has a range of all real numbers (from -∞ to +∞), so it certainly includes 0.4.
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y = csc x: The cosecant function is defined as the reciprocal of the sine function. Since the sine function has a range from -1 to 1, the cosecant function's range is (-∞, -1] ∪ [1, +∞). Therefore, it does not include 0.4.
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y = sin x: The range of the sine function is from -1 to 1, so it does include 0.4.
From this analysis, the only function whose range does not include 0.4 is:
y = csc x.