Final answer:
The factored form of a quadratic equation is helpful because it allows for identifying roots, simplifies the equation, and aids in graphing. Therefore, all the given options are correct.
Step-by-step explanation:
The factored form is helpful in solving quadratic equations because it simplifies the equation and reveals the roots directly. When a quadratic equation is in the form ax²+bx+c = 0 and can be factored into (mx+n)(px+q) = 0, setting each factor equal to zero, namely mx+n = 0 and px+q = 0, gives us the roots or solutions to the equation. Moreover, the factored form aids in the graphing of quadratic functions by providing the x-intercepts, which are the roots of the equation.
In conclusion, the factored form is crucial for identifying the roots of a quadratic equation, simplifying the equation, and facilitating its graphical representation, thus making 'd. All of the above' the correct choice.