The quadratic formula is a method that is used to find the roots of a quadratic equation. Several methods have been proposed for the solution of quadratic equations.
For a general quadratic equation of the form:
`ax^2 + bx + c = 0`
where a,b,c are constants (can be -ve) and where a !=0, the quadratic formula is given by
This formula is so important that you must learn it by heart for good
According to this solution, there are two roots of the quadratic equation. And they are given as:
`x=(-b+sqrt(b^2-4ac))/(2a) ` , ` x=(-b- sqrt(b^2-4ac))/(2a) `
i.e. one with the positive sign, while the other has a negative sign.
In the expression for the roots of a quadratic equation, the term present inside the square root `(b^2-4ac)` is termed as discriminant and the value of this expression is of great significance.
There are 3 different possibilities with regards to the value of discriminant and the consequences of each type of value have been discussed below:
If the discriminant has a positive value, the two roots of the quadratic equation are both distinct and real.
If the discriminant is equal to zero, the two roots are equal and real.
The third possibility arises when the discriminant is negative i.e. less than zero. In this case, the two roots are distinct and conjugate complex number.