is there any formula or neat trick to factorise a cubic equation like x^3 + 4x^2 -28x + 32=0?
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Originally Posted by Tekken is there any formula or neat trick to factorise a cubic equation like x^3 + 4x^2 -28x + 32=0? Yes, use the factor and remainder theorems. For any polynomial , if then is a factor. The factors of are . So try substituting these values into the expression.
That will allow you to find any factors with rational coefficients. More generally, you could use Cardano's cubic formula to find a solution, , then divide by to reduce the problem to factoring a quadratic.
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