SAT Math Multiple Choice Question 484: Answer and Explanation
Each of the following quadratic equations represents the graph shown above. Which equation reveals the exact values of the x-intercepts of the graph?
Correct Answer: A
Category: Passport to Advanced Math / Quadratics
Strategic Advice: Quadratic equations can be written in several forms, each of which reveals something special about the graph. For example, the vertex form of a quadratic equation gives the minimum or maximum value of the function, while the standard form reveals the y-intercept.
Getting to the Answer: The factored form of a quadratic equation reveals the solutions to the equation, which graphically represent the x-intercepts. Choice (A) is the only equation written in this form and therefore must be correct. You can set each factor equal to 0 and solve to find that the x-intercepts of the graph are and .