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(a)

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The function is $\"\"$ .

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The derivative of the function can be found in two ways.

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One is differentiating the function directly and then simplifying.

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Other is by simplifying the function and differentiating the simplified function.

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$\"\"$

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Apply derivative on each side with respect to $\"\"$ .

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$\"\"$

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$\"\"$

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Apply power rule of differentiation: $\"\"$ .

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$\"\"$

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$\"\"$ .

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The function is $\"\"$ .

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Trigonometric identities : $\"\"$ .

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$\"\"$

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Apply derivative on each side with respect to $\"\"$ .

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$\"\"$

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$\"\"$ .

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(b)

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The functions are $\"\"$ and $\"\"$ .

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Consider $\"\"$ .

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Apply derivative on each side with respect to $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Consider $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$

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Substitute $\"\"$ in the above expression.

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$\"\"$ .

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(a) $\"\"$ .

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(b) $\"\"$ .