Quadratic Formula Definition

Quadratic formula definition & explanation:

Now let us define quadratic formula. The quadratic formula provides means of solving quadratic equations in algebra. So what is the quadratic formula? For a equation
ax2 + bx + c=0
the quadratic equation formula for x is 
quadratic formula
where x represents variable to be solved that justifies
quadratic formula definition, with a, b and c being constant for all a not equal to 0. a is in denominator and hence can't be 0 value. Since it is a second degree equation, the quadratic equation has 2 solutions for x, also known as roots identified by "±" in above formula. If you find the quadratic equation too difficult to solve, you just need to know what is quadratic formula for it. Once you know it, you can easily solve for the roots.

Example showing solution to Quadratic Formula:

Suppose you want to solve for for x2 + 3x – 4=0 , It can further be written as (x+4)(x-1)=0, that give -4 and 1 as the roots to quadratic equation. Now let us verify it using quadratic formula. If we compare the equation with  ax2 + bx + c =0 , we have a=1, b=3 and c=-4. Now using the above formula,
quadratic equation

Thus we get same solution as we did it manually. Since this was a simple equation, it was very easy to get the answer by just looking at the equation. But this is not the case in many complex scenarios. In such situations, quadratic equations helps a lot getting the solution. They are also important for finding solution in terms of imaginary complex numbers. Let us consider b2-4ac as the discriminant. If the discriminant value is less than 0 i.e. negative, taking a square-root of negative number becomes complex number, thus the equation generating complex roots. Let us solve it for x2-10x+34=0. Here we have a=1, b=-10 and c=34. As it is clear that discriminant value is -36<0, it will generate complex roots. Now let us solve using the formula.

quadratic formula solution

Thus it generates 2 complex roots as shown where i2=-1.


Ian Roberts
Engineer
San Francisco, USA

"If you're at school or you just deal with mathematics, you need to use Studygeek.org. This thing is really helpful."
Lisa Jordan
Math Teacher
New-York, USA

"I will recommend Studygeek to students, who have some chalenges in mathematics. This Site has bunch of great lessons and examples. "
John Maloney
Student, Designer
Philadelphia, USA

" I'm a geek, and I love this website. It really helped me during my math classes. Check it out) "
Steve Karpesky
Bookkeeper
Vancuver, Canada

"I use Studygeek.org a lot on a daily basis, helping my son with his geometry classes. Also, it has very cool math solver, which makes study process pretty fun"