Help with this question pls:)

Which undefined geometric term is described as a location on a coordinate plane that is designed by an ordered pair (x,y) ?

Cot(90° − x) = 1 the value of x that satisfies this equation is °. a. 60 b. 135 c. 225 d. 315

Which function represents the sequence? f(n)=n+3 f(n)=7n−4 f(n)=3n+7 f(n)=n+7