Fit a Quadratic to Function Data

When finding the curve of best fit in Desmos, what do I do after I entered my table of coordinates?

• plot the points

• y₁ ~ ax₁ +b

• y₁ ~ ax₁² +bx₁ + c

• do a little dance

If this is an equation for a curve of best fit, find the output (y) when the input (x) is 13:

y = 1.2x² - 3.7x - 19

• -51.5

• 135.7

• 154.7

• 183,8

A scientist dropped an object from a height of 200 feet. She recorded the height of the object in 0.5-second intervals. Her data is shown.

Based on a quadratic model, which best approximates the height at 3 seconds?

• 52 feet

• 55 feet

• 65 feet

• 80 feet

When using Desmos to find the curve of best fit, what do I need to enter first?

• y₁ ~ ax₁² +bx₁ + c

• the equation

• the table/chart of values

• the vertex

In the equation y = x² +5x +7, match each coefficient with its correct letter

• a=0, b=5, c=7

• a=1, b=5, c=7

• a=7, b=5, c=1

Based on this pattern, would a Linear or Quadratic model be most appropriate?

• Quadratic

• Linear

Match the table with the correct equation:

• y = -.08x² + 5.94x +28.80

• y = -1.2x² + 3.2x +3.2

• y = 0.5x +9

• y = 0.7 x² + 2.7x +8.7

Match the table with the correct equation:

• y = -.08x² + 5.94x +28.80

• y = -1.2x² + 3.2x +3.2

• y = 0.5x +9

• y = 0.7 x² + 2.7x +8.7

Which equation corresponds to the values in this table?

• y = 4 - x

• y = 4 - x²

• y = x² - 4

• y = -2x - 1

Using the Curve of Best fit for #11. Predict the value of y when x = 3.

• 5

• 7

• 9

• 11