Step 1:

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The curve is $\"\"$ and $\"\"$

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Consider $\"\"$

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Differentiate with respect to $\"\"$ .

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$\"\"$

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Consider $\"\"$

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Differentiate with respect to $\"\"$ .

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$\"\"$

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$\"\"$

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Find $\"\"$ .

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$\"\"$

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Find $\"\"$ .

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$\"\"$

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Consider $\"\"$ .

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For concave upwards $\"\"$

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$\"\"$

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Multiplying by negative sign will reverse the inequality.

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$\"\"$

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$\"\"$

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Secant value is negative in Second and third quadrant that is $\"\"$ .

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Hence, the curve is concave upwards in $\"\"$ .

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Solution:

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$\"\"$ , $\"\"$ and

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The curve is concave upwards in $\"\"$ .

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