What is the common difference for the sequence shown below?

Ihave trouble finding the nth term of a linear sequence

The function y= x - 4x+ 5 approximates the height, y, of a bird, and its horizontal distance, x, as it flies from one fence post to another. all distances are in feet. complete the square to find and interpret the extreme value (vertex). select two answers: one extreme value and one interpretation.

Which angle has the same measure as the dehedral angle formed by the orange face and the purple rectangle