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.
1 Identify the form of the expression. 2  It is a quadratic trinomial with coefficients a = 1, b = 6, and c = â5. 3  Its discriminant is D = b 2 â 4 Â· a Â· c = 6 2 â 4 Â· 1 Â· (â5) = 56, which is not a perfect square so we must factor the expression using the completing the square method. If D is negative then the above formula contains the square root of a negative number. 2  Over the real numbers this is not allowed and means that the quadratic trinomial can't be factored, but over the complex numbers this is no problem. 3  This case is described in detail below. 4  Identify the form of the expression.