Write and equation using sine that descriptions the graph on the left

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

Someone which statements are true? check all that apply.

Atest consists of 10 multiple choice questions, each with 5 possible answers, one of which is correct. to pass the test a student must get 60% or better on the test. if a student randomly guesses, what is the probability that the student will pass the test?