The Cubic Equation
نویسنده
چکیده
As is well known, equations of degree up to 4 can be solved in radicals . The solutions can be obtained, apart from the usual arithmetic operations, by the extraction of roots. In the case of the quadratic equation, this has a very concrete meaning. Even if the coefficients are arbitrary complex numbers, the solutions can always be calculated by the extraction of roots from nonnegative real numbers. This can, if necessary, even be done by hand. It is therefore important to emphasize that, already in the case of the cubic equation with only real coefficients, solvability in radicals means much less. Whenever there are three distinct real solutions, calculating them involves finding a solution to the equation
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