Drawing a quadratic function

There are many ways to draw a quadratic function,the way i use is quick and easy.


Let's use y=4x²+8x-12 as an example.


  • Step 1.

I will factor this thing into,y=4(x²+2x-3) because i observed the 3 terms all have a GCF of 4.


  • Step 2.

Now i can do more factoring,and factor it into y=4(x-1)(x+3).So now we know when we input 1 and -3,we will have the x intercept.


  • Step 3.

Now we will have to find the vertax,vertex typically means a corner or a point where lines meet. For example a square has four corners, each is called a vertex.

In order to find the vertax you need the X value first.To do that,we use 4 to multiply -1,and add -4 to 3,which gives you -1,because the vertex is always right at the middle of the two x intercept.So now,we input -1 and get a output of  -16.we then mark a dot on (-1,-16),and(1,0)(-3,0).The last step is easy,so i combine them,we draw a cruve through the 3 dots,and a quadratic function is graphed!


like this


Now we are done with quadratic functions! go do some practices!


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