Final answer:
To write the first expression in terms of the second expression when the terminal point determined by t is in quadrant III, rewrite the expression as -tan(t) = -cos(t).
Step-by-step explanation:
To write the first expression in terms of the second expression when the terminal point determined by t is in quadrant III, we need to consider the signs of the trigonometric functions in that quadrant. In quadrant III, both tan(t) and cos(t) are negative. Therefore, we can rewrite the first expression as:
-tan(t) = -1 * cos(t)
So, the first expression in terms of the second expression when the terminal point determined by t is in quadrant III is -tan(t) = -cos(t).