I have the equation x²+4x+3 and I have the x values of:

-5,-4,-3,-2,-1,0,1,2,3,4,5

Relevance
• Anonymous
6 years ago

Find the vertex (h,k)

h= -b/2a

h= -4/2(1)

h= -2

k= c - (b²/4a)

k= 3 - (4²/4a)

k= 3 - (16/4(1))

k= 3-4

k = -1

You could also complete the square to find the vertex but I just chose this way coz its faster.

Use the building rule for quadratic equations

1 ---> 1

2 ---> 4

3 ---> 9

Since the "a" value is one, you don't need to multiply the right side (1, 4, 9) of the building rule and leave it as is.

Plot (-2, -1) on your grid and move 1 space to the right and 1 space up and plot a point. Now move 1 space to the left from the vertex and 1 space up and plot a point. Thats the first part of the building rule.

Now, move 2 spaces to the right of the vertex and 4 spaces upwards and plot a point. Do the same by moving 2 spaces to the left of the vertex and 4 spaces upwards. Thats the second part of the building rule.

Now move 3 spaces to the right of the vertex and 9 spaces upwards and plot a point. Do the same by moving 3 spaces to the left of the vertex and 9 spaces upwards. Thats the third part of the building rule.

Connect the points and you're done :)