The temperature, $H$, in degrees Celsius, of a cup of coffee placed on the kitchen counter is given by $H = f(t)$, where $t$ is in minutes since the coffee was put on the counter.

(a) Is $f'(t)$ positive or negative? ? positive negative
(Be sure that you are able to give a reason for your answer.)

(b) What are the units of $f'(35)$? help (units)

Suppose that $|f'(35)| = 1.5$ and $f(35) = 68$. Fill in the blanks (including units where needed) and select the appropriate terms to complete the following statement about the temperature of the coffee in this case.
At minutes after the coffee was put on the counter, its ? derivative temperature change in temperature is and will ? increase decrease by about in the next 30 seconds.