What is the radius of the circle x^2 + y^2 - 6x = 0? Date of Exam May 1995 Subject Mathematics, Surveying and Transportation Engineering Problem What is the radius of the circle $x^2 + y^2 - 6x = 0$? A. 6 C. 4 B. 9 D. 3 Answer Key Click here to show or hide the answer key [ D ] Solution Click here to expand or collapse this section $x^2 + y^2 - 6x = 0$ $(x^2 - 6x) + y^2 = 0$ $(x^2 - 6x + \color{#FFFF66}{9}) + y^2 = \color{#FFFF66}{9}$ $(x - 3)^2 + y^2 = 3^2$ Standard Equation of Circle $(x - h)^2 + (y - k)^2 = r^2$ center = (3, 0) radius = 3 ← answer Category Analytic Geometry Circle General Equation of Circle Standard Equation of Circle Radius of Circle Log in or register to post comments