Use the vertical line test to determine to determine whether the graph is the graph of a function

What basic trigonometric identity would you use to verify that csc x sec x cot x = csc^(2)x

What is the equation of the linear function represented by the table?

In triangle abc segment de is parallel to the side ac . (the endpoints of segment de lie on the sides ab and bc respectively). find de, if ac=20cm, ab=17cm, and bd=11.9cm;