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Which of the following continuous functions are uniformly continuous on the specified set? Justify your answers. Use any theorems you wish.

(a) f(x)=x¹⁷sin x-eˣ cos 3 x on [0, π],
(b) f(x)=x³ on [0,1]
(c) f(x)=x³ on (0,1)
(d) f(x)=x³on ℝ
(e) f(x)=1/x³ on (0,1]
(f) f(x)=sin1/x² on (0,1],
(g) f(x)=x² sin1/x on (0,1].

1 Answer

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Final answer:

The functions that are uniformly continuous on the specified set are: a) f(x) = x¹⁷sin(x) - eˣcos(3x) on [0, π], b) f(x) = x³ on [0,1], d) f(x) = x³ on ℝ, and e) f(x) = 1/x³ on (0,1].

Step-by-step explanation:

To determine which of the given functions are uniformly continuous on the specified set, we can apply the theorem which states that a function is uniformly continuous on a closed and bounded interval if and only if the function is continuous on the interval.

(a) The function f(x) = x¹⁷sin(x) - eˣcos(3x) is continuous on the closed interval [0, π], so it is uniformly continuous on this interval.

(b) The function f(x) = x³ is continuous on the closed interval [0, 1], so it is uniformly continuous on this interval.

(c) The function f(x) = x³ is not continuous on the open interval (0, 1), so it is not uniformly continuous on this interval.

(d) The function f(x) = x³ is continuous on the entire real line ℝ, so it is uniformly continuous on this interval.

(e) The function f(x) = 1/x³ is continuous on the closed interval (0, 1], so it is uniformly continuous on this interval.

(f) The function f(x) = sin(1/x²) is not continuous at x = 0 on the open interval (0, 1], so it is not uniformly continuous on this interval.

(g) The function f(x) = x²sin(1/x) is not continuous at x = 0 on the open interval (0, 1], so it is not uniformly continuous on this interval.

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