Relationship between Zeroes and Coefficients of a Polynomial

For Quadratic Polynomial:
If α and β are the roots of a quadratic polynomial a{x^2} + bx + c, then,

\alpha  + \beta  =  - b/a

Sum of zeroes = -coefficient of x /coefficient of {x^2}

\alpha \beta  = c/a

Product of zeroes = constant term / coefficient of {x^2}

For Cubic Polynomial

If \alpha ,\beta and \gamma are the roots of a cubic polynomiala{x^3} + b{x^2} + cx + d, then

\begin{array}{l}\alpha  + \beta  + \gamma  =  - b/a\\\alpha \beta  + \beta \gamma  + \gamma \alpha  = c/a\\\alpha \beta \gamma  =  - d/a\end{array}

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