Final answer:
The coordinates of the other endpoint Q are (-3, -6).
Step-by-step explanation:
The midpoint of a line segment is the average of the coordinates of the endpoints. To find the coordinates of the other endpoint, we can use the formula (x1+x2)/2 and (y1+y2)/2 for the midpoint M(-1,-4) and endpoint P(1,-2).
Plugging in the values, we get (x1+1)/2 = -1 and (y1+(-2))/2 = -4. Solving these equations, we find x1 = -3 and y1 = -6.
Therefore, the coordinates of the other endpoint Q are (-3, -6).