Graphing Quadratics?

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

1 Answer

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  • Anonymous
    6 years ago
    Favorite Answer

    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 :)

    Source(s): Grade 12 math student
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