Which graph represents an function

Acredit card advertises an annual interest rate of 23%. what is the equivalent monthly interest rate?

The coordinates r(1, -3), s(3, -1) t(5, -7) form what type of polygon? a right triangle an acute triangle an equilateral triangle an obtuse triangle

Given that sin∅ = 1/4, 0 < ∅ < π/2, what is the exact value of cos∅? a. (√4)/4 b. (√15)/4 c. (4π)/2 d. (4√2)/4