$\"\"$

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The function is $\"\"$ and $\"\"$ .

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The function is polynomial function, it is continuous in the interval $\"\"$ .

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$\"\"$

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Differentiate on each side with respect to $\"\"$ .

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$\"\"$

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$\"\"$

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Derivative of the function is $\"\"$ which is positive in the interval $\"\"$ .

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So the function is one to one function and monotonic.

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$\"\"$

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Consider $\"\"$ .

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Therefore $\"\"$ .

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$\"\"$

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The solution of the polynomial is

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$\"\"$ .

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Imaginary roots are not considered, hence $\"\"$ is the solution.

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Therefore $\"\"$ then $\"\"$ .

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Find $\"\"$ .

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$\"\"$

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$\"\"$ .

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Property of inverse function : $\"\"$ .

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$\"\"$

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The derivative of inverse function is $\"\"$ .

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$\"\"$

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The derivative of inverse function is $\"\"$ .