How to Make a Quadratic Function (Parabola Graphic)

Firstly, you have to recognize about the equation. You can identify the equation whether it have an upward curve or downward curve.

It can seems from the value of a in general quadratic equation like f(x) = ax²+ bx + c, where f(x) = y for a, b, c € R and a ≠ 0.

If the value of a is positive, hence the quadratic equation have an upward curve. However, if the value of a is negative, hence the quadratic equation have a downward curve.

2.      After that, determine the intersection points toward to the x-axis and y-axis.

We determine the intersection point toward to the x-axis, hence the value of y is y = 0. When we determine the intersection point toward to the y-axis, hence the value of x is x = 0.

3.      The next step is you have to determine a symmetric point and a maximum or minimum point as an extreme point.

A symmetric point can determine by  , 

while a maximum or minimum point can determine by  

for the discriminant by D = b² - 4ac.

Hence you find the extreme point like .

4.      Now, you have many points such as the intersection points toward to the x-axis and y-axis, a symmetric point and a maximum or minimum point as an extreme point. After that you sketch the graph by put those points have you got and connected those points smoothly.

 #Fransiska Indah

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