$\"\"$

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

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Here $\"\"$ are the zeros of $\"\"$ .

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If $\"\"$ then $\"\"$ is a factor of $\"\"$ .

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If $\"\"$ then $\"\"$ is a factor of $\"\"$ .

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If $\"\"$ then $\"\"$ is a factor of $\"\"$ .

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The cubic function is in the form of $\"\"$ , where $\"\"$ are zeroes of the function.

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$\"\"$ (1)

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$\"\"$

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$\"\"$ .

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The function $\"\"$ at $\"\"$ is $\"\"$ .

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Substitute $\"\"$ and $\"\"$ in equation (1).

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$\"\"$

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$\"\"$

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Substitute $\"\"$ in equation (1).

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$\"\"$

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The cubic function is $\"\"$ .

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$\"\"$

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The cubic function is $\"\"$ .