(a) Describe a possible graph of the temperature, T, on an east-west line through Durango, Colorado, if the origin is at Durango, the positive x-axis corresponds to east of Durango, and the vertical z-axis is the temperature. For negative x within a few hundred miles of the origin, the sign of $T'(x)$ is ? Positive Negative Zero , while for positive x a few hundred miles from the origin, the sign of $T'(x)$ is ? Positive Negative Zero . We estimate that $T(0) =$ ? 50 51 52 53 54 55 56 57 58 59 60 degrees Fahrenheit.

(b) Describe a possible graph of the temperature, T, on a north-south line through Des Moines, Iowa, if the origin is at Des Moines, the positive y-axis corresponds to north of Des Moines, and the vertical z-axis is the temperature. For negative y within a few hundred miles of the origin, the sign of $T'(y)$ is ? Positive Negative Zero , while for positive y a few hundred miles from the origin, the sign of $T'(y)$ is ? Positive Negative Zero . We estimate that $T(0) =$ ? 50 51 52 53 54 55 56 57 58 59 60 degrees Fahrenheit.