M1L1 Successive Differences

When the 1st differences are equal, it is a ______ function.

• linear

• quadratic

• exponential

• cubic

y = 4x - 1

• m=4 and yintercept is 1

• m=-4 and yintercept is -1

• m=4 and yintercept is -1

• m=-1 and yintercept is 4

Tags

CCSS.8.EE.B.6

CCSS.8.F.A.3

What are the 1st differences?

• +8, so it is linear

• -8, so it is linear

• +2, so it is linear

• +8, so it is quadratic

When the 2nd differences are equal, it is a ______ function.

• linear

• quadratic

• exponential

• cubic

Which is NOT true?

• 1st differences are not equal

• 2nd differences are equal

• 1st differences are equal

• it is quadratic

Which of the following equations represents the "general" standard form of a quadratic (2nd degree) equation?

• ax + by = c

• y = a(x - h)² + k

• y = ax² + bx + c

• y = mx + b

3rd degree relationships may also be described as ________.

• Linear

• Quadratic

• Cubic

• None

Zach was making a table of 1st and 2nd differences for a quadratic function. Where is his mistake?

• What are you talking about? There's no mistake!

• He messed up on the first-first difference (red one). It should be a positive 2.

• He messed up on the second-first difference (blue one). It should be a positive 2.

• He messed up on the third-first difference (green one). It should also be -2.

Mary created the following table of first and second differences for a given list of x and y values. Mark all correct answers.

• Mary's equation is quadratic because the second differences are all the same.

• Mary's equation is cubic because the second differences are all the same.

• Mary can use her results to calculate that the next y value is going to be 68.

• Mary can use her results to calculate that the next y value is going to be 17.

Mary created the following table of first and second differences for a given list of x and y values. How can she use this list to determine what a, b, and c are for the quadratic equation (ax² + bx + c)? Mark all correct answers.

• c = -4 because that is the y value when x = 0.

• a = 1 because the second differences are always 2a on a quadratic equation and 2a = 2.

• b = 6 because a + b (the first-first difference) = 7, so 1 + b = 7

• This problem is unsolvable because you need a 3rd difference.