Equação de segundo grau

Fórmula de Bhaskara

An equation is a mathematical expression that has in its composition unknowns, coefficients, exponents, and an equal sign. The equations are characterized according to one of highest power unknowns. see: 

2x + 1 = 0, the exponent of the unknown x is equal to 1. Accordingly, this equation is ranked as the 1st grade. 

2x ² + 2x + 6 = 0, we have two unknowns x in this equation, one of which has the largest exponent, determined by 2. This equation is classified as 2nd degree. 

x ³ - x ² + 2x - 4 = 0, in which case there are three unknowns x, where the largest exponent equal to 3 determines that the equation is classified as the third degree. 

Each model equation has a form of resolution. Work as a resolution of an equation of the 2nd degree, using the method of Bhaskara. Determine the solution of an equation figure is the same as the roots, that is, the value or values ​​that satisfy the equation. For example, the roots of the 2nd degree equation x ² - 10x + 24 = 0 are x = 4 or x = 6 because: 

Substituting x = 4 in the equation, we have: 

x ² - 10x + 24 = 0 
4 ² - 10 * 4 + 24 = 0 
16-40 + 24 = 0 
-24 + 24 = 0 
0 = 0 (true) 

Substituting x = 6 into the equation, we have: 

x ² - 10x + 24 = 0 
6 ² - 10 * 6 + 24 = 0 
36 - 60 + 24 = 0 
- 24 + 24 = 0 
0 = 0 (true) 

We can see that the two values ​​satisfy the equation. But how do we determine the values ​​that make the equation a true sentence? It is this way of determining the unknown values ​​that we discuss below. 

We will determine the method of resolving the values ​​of Bhaskara equation of the 2nd degree: x ² - 2x - 3 = 0.