Normally a domestic freezer is best set to â18 Â°C (0 Â°F) or colder, as that's what the expiration dates for many food items are based on. It's also a requirement for freezers in restaurants, supermarkets & other places that sell food (at least here in Europe) to maintain a temperature of at most -18 Â°C.
Note: When you're dealing with quadratic equations, it can be really helpful to identify a, b, and c. These values are used to find the axis of symmetry, the discriminant, and even the roots using the quadratic formula. It's no question that it's important to know how to identify these values in a quadratic equation.
Factoring can make solving for roots of cubic equations quicker and easier as well. For example, the cubic equation x^3 + x^2 - x - 1 cannot be solved with the quadratic equation. The cubic formula*  can be of some help, but there is a faster way.or example, solving x^2 + 2x + 1 is easy with the quadratic formula, but knowing how to factor this equation makes solving for the roots quicker.