College Algebra CLEP Prep Practice Exam

Which of the following is the vertex of the parabola y = 8x^2-10x-11?

1. (-1.5, 37.5)

2. (-1.5, -19.5)

3. (1, 7)

4. (1, -9)

The correct answer is: (-1.5, -19.5)

The vertex of a parabola is the highest or lowest point on the curve, and it is located at the point where the parabola changes direction. In this case, the parabola is in the form of y = ax^2 + bx + c, where the vertex can be found at the point (-b/2a, c-(b^2/4a)). In the given equation, the coefficient of x^2 is 8, and the coefficient of x is -10. Plugging these values into the formula, we get the x-coordinate of the vertex as -(-10)/2(8) = -1.25. To find the y-coordinate, we plug this x value back into the equation and get y = 8(-1.25)^2-10(-1.25)-11 = -19.5. Thus,