#Methods of solving quadratic equations how to#
#Methods of solving quadratic equations plus#

As 100 100 is a perfect square, there will be two rational solutions.ī 2 − 4 a c = ( −5 ) 2 − 4 ( 3 ) ( −2 ) = 49. For example, expand the factored expression ( x − 2 ) ( x + 3 ) ( x − 2 ) ( x + 3 ) by multiplying the two factors together.Ĭalculate the discriminant b 2 − 4 a c b 2 − 4 a c for each equation and state the expected type of solutions.ī 2 − 4 a c = ( 4 ) 2 − 4 ( 1 ) ( 4 ) = 0. So, in that sense, the operation of multiplication undoes the operation of factoring.

#Methods of solving quadratic equations plus#

Multiplying the factors expands the equation to a string of terms separated by plus or minus signs. In other words, if the product of two numbers or two expressions equals zero, then one of the numbers or one of the expressions must equal zero because zero multiplied by anything equals zero. Solving by factoring depends on the zero-product property, which states that if a ⋅ b = 0, a ⋅ b = 0, then a = 0 a = 0 or b = 0, b = 0, where a and b are real numbers or algebraic expressions. If a quadratic equation can be factored, it is written as a product of linear terms. Factoring means finding expressions that can be multiplied together to give the expression on one side of the equation. Often the easiest method of solving a quadratic equation is factoring. They are used in countless ways in the fields of engineering, architecture, finance, biological science, and, of course, mathematics. For example, equations such as 2 x 2 + 3 x − 1 = 0 2 x 2 + 3 x − 1 = 0 and x 2 − 4 = 0 x 2 − 4 = 0 are quadratic equations. Solving Quadratic Equations by FactoringĪn equation containing a second-degree polynomial is called a quadratic equation.

#Methods of solving quadratic equations how to#

If there is a limited amount of space and we desire the largest monitor possible, how do we decide which one to choose? In this section, we will learn how to solve problems such as this using four different methods. Proportionally, the monitors appear very similar. Any other quadratic equation is best solved by using the Quadratic Formula.The computer monitor on the left in Figure 1 is a 23.6-inch model and the one on the right is a 27-inch model. If the equation fits the form ax 2 = k or a( x − h) 2 = k, it can easily be solved by using the Square Root Property. If the quadratic factors easily, this method is very quick.

How to identify the most appropriate method to solve a quadratic equation.

if b 2 − 4 ac < 0, the equation has 2 complex solutions.

if b 2 − 4 ac = 0, the equation has 1 real solution.

If b 2 − 4 ac > 0, the equation has 2 real solutions.

For a quadratic equation of the form ax 2 + bx + c = 0,.

Using the Discriminant, b 2 − 4 ac, to Determine the Number and Type of Solutions of a Quadratic Equation.

Then substitute in the values of a, b, c.

Write the quadratic equation in standard form, ax 2 + bx + c = 0.

$methods of solving quadratic equations$

How to solve a quadratic equation using the Quadratic Formula.We start with the standard form of a quadratic equation and solve it for x by completing the square. Now we will go through the steps of completing the square using the general form of a quadratic equation to solve a quadratic equation for x. We have already seen how to solve a formula for a specific variable ‘in general’, so that we would do the algebraic steps only once, and then use the new formula to find the value of the specific variable. In this section we will derive and use a formula to find the solution of a quadratic equation. Mathematicians look for patterns when they do things over and over in order to make their work easier. By the end of the exercise set, you may have been wondering ‘isn’t there an easier way to do this?’ The answer is ‘yes’. When we solved quadratic equations in the last section by completing the square, we took the same steps every time. Solve Quadratic Equations Using the Quadratic Formula