Draw the related diagram:
\ and
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Consider function on interval
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Maximize , minimize
.
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Derivative on each side with respect to .
Derivative of inverse trigonometric formula: .
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Find the critical numbers by equating derivative to zero.
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The solutions of are
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and
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The critical numbers are and
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is not in the interval
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The critical number is .
Substitute .
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The function has minimum at
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Therefore, is maximum at
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Substitute in
.
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The absolute maximum is .
is maximum at
.
is maximum at
.