It is a straight-forward method where we can plug in numbers directly into the quadratic formula to get the answers to the equation.

A general form of the quadratic equation is

**ax**

^{2}+ bx + c = 0.The

**quadratic formula**is x = [-b +- sqrt(b

^{2}-4ac) ]/ 2a

where x is the answers to the quadratic equation.

Example: 3x

^{2}+ 4x - 1 = 0 is a quadratic equation.

To solve the above, what we need is to identify the value for "a", "b" and c" ( called the coefficient).

Here a = 3, b= 4 and c = -1.

Next putting the numbers of above into the quadratic formula will allow us to get the answers directly. That is it! Nothing difficult!

**However mistakes using quadratic formula do occur !**Why?

*Never see the coefficient properly - that's why!*

To apply the quadratic formula, we need to

__clearly identify the correct coefficient__.

Example : 5x + 6x

^{2}- 4 = 0.

Here a = 6 (not 5) since "a" belongs to the x

^{2}term in the quadratic equation.

and b = 5 (not 6) as "b" belongs to the x term of the equation.

c = -4 (no doubt about it)

Message: You do not look for the position of the a, b and c. You look for the term associated with the x

^{2}and x symbol.

- 'a' always belongs t the term with the power of 2 (e.g. x
^{2)}, - 'b' belongs to the term with power of 1 (e.g. x), and
- 'c' belongs to the term with power of 0.

Thus to use quadratic formula to solve quadratic equation, the only caution is for you to identify the correct coefficient.

**Another common that is always made :**The general quadratic equation is ax

^{2 }+ bx + c = 0.

**NOTE**: the equation = 0 .

If the quadratic question is 4x

^{2}- 3x + 2 = x, what then are the value of 'a, 'b' and c'?

We need to ensure that the given equation matches the general quadratic equation form

**we can proceed to identify the 'a', 'b' and 'c'.**

*before*The answer for above is 'a' = 4, 'b' =

**-3 -1 = -4**, and 'c' = 2.

**Advice:**Just be careful that the final quadratic equation must = 0 before we do anything.

Clear?

Maths needs some form of mental discipline to get results. It serves you good in the long run.

.

## No comments:

Post a Comment