Must a function this is decreasing over a given interval always be negative over the same interval? explain

It is certainly possible for a function decreasing over a certain interval to be negative, but no rule that says it must be. On the other hand, where the function is decreasing, the rate of change of the function must be negative.

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq