The Shape of the Model Described by the Equation $E ( y ) = \beta _ { 0 } + \beta _ { 1 } x + \beta _ { 2 } x ^ { 2 }$

Multiple Choice

The shape of the model described by the equation $E ( y ) = \beta _ { 0 } + \beta _ { 1 } x + \beta _ { 2 } x ^ { 2 }$ could be:

A) parabolic resembling an upright"U".
B) parabolic resembling an upside-down"U".
C) a straight line with an intercept $\beta _ { 0 }$ and slope $\beta _ { 2 } / \beta _ { 1 }$ .
D) a straight line with an intercept $\beta _ { 0 }$ and slope $\beta _ { 1 } / \beta _ { 2 } .$ .
E) Both A and B.