graphing f(x)= -4x^2

Question

Please help me graph  f(x)= -4x²   

 

I don't know where to begin.....thank you

Answer 1

Hi Raul,

 

In response to your question,

 

Step 0 - Introduction

 

This problem is likely asking you to make a plot of f(x) vs. x in a 2-Dimensional "Cartesian" space.

Perhaps a simpler way to think about it,

This basically amounts to making a graph of y vs. x.

You can think of "y" as being a synonym for "f(x)".

 

Other naming schemes include:

calling "f(x)" the dependent variable and calling "x" the independent variable.

This is because f(x) is a function of x, and therefore f(x) depends on x, while, x does not necessarily depend on anything.

 

or:

you can also choose to think about "f(x)" a.k.a "-4x² " as the output

and "x" as the input

 

typically in these cases, it is easiest to make a table of the form:

 

x             y
x₁          y₁
x₂          y₂
x₃          y₃
x₄          y₄
x₅          y₅

 

 

Step 1- Make a Table

 

It may be simplest to start with making a table that looks something like this

x          f(x)

 

-2         -4(-2)² 

-1         -4(-1)²

0          -4(0)²

1          -4(1)²

2          -4(2)²

 

Once you've completed that step you can simplify the second column of the table to find the numerical value.

 

Step 2 - Plot (graph) your results

 

Finally to graph the results

draw a graph with an x-axis, and a y-axis.

plot the points from your table on the x-axis and y-axis.

 

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I hope you found this somewhat helpful.

If you need more help, please consider visiting my profile.

-Michael

http://www.wyzant.com/Tutors/Michaels_Tutoring

 

 

 

 

Answer 2

Click on the link below for a quick and easy guide to graphing quadratic equations.

 

http://www.wyzant.com/resources/files/263613/how_to_graph_a_quadratic_equation