Matematické Fórum

stuart clark · 04. 11. 2011 04:02

Consider the cubic equation given by $x^3+ax^2+bx+c = 0$ , where $a, b, c$ are real numbers. Which of the following is correct :

$(1)$ . If $a^2-2b < 0,$ then the equation has one real and two imaginary roots

$(2)$ . If $a^2-2b\geq 0,$ then the equation has all real roots

$(3)$ . If $a^2-2b > 0,$ then the equation has all real and distinct roots

$(4)$ . If $4a^3-27b^2 >0,$ then the equation has real and distinct roots.

Matematické Fórum

#1 04. 11. 2011 04:02

analysis of cubic equation

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