Mathematics 2014 JAMB Past Questions - Question 40: Find the minimum value of y=x2-2x-3.

Correct Answer

A

Explanation

To find the minimum value of the quadratic function y = x^2 - 2x - 3, we can use the concept of vertex.The vertex of a quadratic function in the form y = ax^2 + bx + c is given by the x-coordinate of the vertex, which is -b/2a, and the y-coordinate of the vertex, which is the value of the function at the x-coordinate of the vertex.In this case, the quadratic function is y = x^2 - 2x - 3, so a = 1, b = -2, and c = -3.The x-coordinate of the vertex is -(-2) / (2 * 1) = 1.To find the y-coordinate of the vertex, we substitute the x-coordinate into the function:y = (1)^2 - 2(1) - 3 = 1 - 2 - 3 = -4.Therefore, the minimum value of y = x^2 - 2x - 3 is -4.