To determine which functions have no zeroes, let's evaluate each option:
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y = cos x: This function has zeroes at odd multiples of π/2 (e.g., π/2, 3π/2, ...). Therefore, it does have zeroes.
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y = cot x: This function has zeroes at integer multiples of π, where x = nπ (n is an integer). Therefore, it does have zeroes.
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y = csc x: The cosecant function is defined as 1/sin x, and since sin x has zeroes at integer multiples of π (where sin x = 0), csc x will be undefined at these points. Therefore, it does not have zeroes.
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y = sec x: The secant function is defined as 1/cos x, and since cos x has zeroes at odd multiples of π/2, sec x will be undefined at these points. Therefore, it does not have zeroes.
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y = sin x: This function has zeroes at integer multiples of π (e.g., 0, π, 2π, ...). Therefore, it does have zeroes.
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y = tan x: This function has zeroes at integer multiples of π where sin x = 0 (x = nπ). Therefore, it does have zeroes.
Based on this analysis, the functions that have no zeroes are:
- y = csc x
- y = sec x
So the correct answers are y = csc x and y = sec x.