To identify the correct equation for the cube root function Sam graphed, we can analyze the characteristics of cube root functions.
A cube root function has the general form:
\[ y = \sqrt[3]{x} + k \]
where \( k \) is a vertical shift. The graph of \( y = \sqrt[3]{x} \) is symmetric about the origin and has an S-shaped curve, which matches the description.
From the responses given:
- \( y = \sqrt[3]{x + 1} - 3 \)
- \( y = 2\sqrt[3]{x - 1} + 3 \)
- \( y = \sqrt[3]{x - 1} + 3 \)
- \( y = 2\sqrt[3]{x + 1} - 3 \)
To find the function that describes an S-shaped curve correctly centered around the origin, we can rule out any linear transformations or shifts that do not represent such behavior.
Of the choices, the one that resembles a basic cube root function related to \( \sqrt[3]{x} \) is:
Option 3: \( y = \sqrt[3]{x - 1} + 3 \)
This function is a transformation of the standard cube root function, shifted to the right by 1 unit and up by 3 units, which retains the S-shaped curve characteristic.
Thus, the correct answer is:
y = \sqrt[3]{x - 1} + 3