What is a quadratic equation and how to solve it
An equation of the form ax 2 + bx + c = 0 is called a quadratic equation.
Solving a quadratic equation means finding its roots x1 and x2, or finding that there are no roots.
The numbers a, b, c - are called the coefficients of the quadratic equation, where a ≠ 0.
The discriminant of a quadratic equation D is expressed by the following formula D = b 2 - 4ac.
First of all, when solving a quadratic equation, it is necessary to find the discriminant.
If D > 0, then the equation has two real roots , which can be found by the formula:
If D = 0, then the roots of the quadratic equation are equal, in fact, the equation has one root , for example 9x 2 = 0.
When D = 0, use the formula:
If D < 0, then the equation has no real roots and the roots of the equation can only be complex numbers , for example, 5x 2 + 6x + 7 = 0, 20x 2 + 2x + 3 = 0.
When D < 0, use the formula: