$\"\"$

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(a)

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The angle of inclination is $\"\"$ .

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Apply chain rule of derivatives:

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$\"\"$

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$\"\"$

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

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$\"\"$ .

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Apply the formula : $\"\"$ .

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$\"\"$

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Apply quotient rule of derivatives: $\"\"$ .

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$\"\"$

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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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The curvature at a point $\"\"$ of a curve is $\"\"$ .

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$\"\"$

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Substitute equation (1) and (2).

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$\"\"$

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$\"\"$ .

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$\"\"$

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(b)

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The parametric curves are $\"\"$ and $\"\"$ .

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$\"\"$ and $\"\"$ .

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$\"\"$ and $\"\"$ .

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Substitute $\"\"$ , $\"\"$ , $\"\"$ and $\"\"$ in $\"\"$ .

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$\"\"$

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$\"\"$

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$\"\"$ .

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$\"\"$

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(a) $\"\"$ .

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(b) $\"\"$ .