parabola with a vertex, algebra homework help

1. Write the equation of a parabola with a vertex of (2, -1) and which opens downward.

2. list three points you might test to find the solution of (x + 3)(x – 5) < 0. Explain why you chose these points.

3. Write a system of equations with one linear equation and one quadratic equation for which (2, 6) is a solution.

4. explain how the graph of y = x2 can be used to graph any quadratic function. Include a description of the effects produced by changing a, h, and k in the equation y = a(x – h)2 + k, and a comparison of the graph of y = x2 and the graph of y = a(x – h)2 + k using values of your own choosing for a, h, and k.

5.explain how you can find the time a trampolinist spends above a certain height. Include a quadratic inequality that describes the time the performer spends more than 10 feet above the ground, and two approaches to solving this quadratic inequality.