

Let us solve this one by Completing the Square.

How many you sell depends on price, so use "P" for Price as the variable what is the best price? And how many should you make?

The method is explained in Graphing Quadratic Equations, and has two steps:įind where (along the horizontal axis) the top occurs using −b/2a: Note: You can find exactly where the top point is! The factors of −15 are: −15, −5, −3, −1, 1, 3, 5, 15īy trying a few combinations we find that −15 and 1 work Multiply to give a×c, and add to give b" method in Factoring Quadratics: There are many ways to solve it, here we will factor it using the "Find two numbers that It looks even better when we multiply all terms by −1: (Note for the enthusiastic: the -5t 2 is simplified from -(½)at 2 with a=9.8 m/s 2)Īdd them up and the height h at any time t is:Īnd the ball will hit the ground when the height is zero: Gravity pulls it down, changing its position by about 5 m per second squared: It travels upwards at 14 meters per second (14 m/s): (Note: t is time in seconds) The height starts at 3 m: Findings about the influence of format on the range of strategies were inconclusive but analysis indicated sporadic evidence of possible influences.Ignoring air resistance, we can work out its height by adding up these three things: Building from Square and Factor Search were the most successful methods of Building a Relationship. Sequence of Differences was the most common strategy, but Building a Relationship was more likely to lead to the right formula. Qualitative analysis of eye-tracking data offers several strategies: Sequence of Differences, Building a Relationship, Known Formula, Linear Recursive and Initial Conjecture. Our aims are to identify their strategies and to explore whether and how format influences these strategies. Participants’ approaches to identifying the nth term were recorded with eye-tracking technology. In this study, we identify ways in which a sample of 18 graduates with mathematics-related first degrees found the nth term for quadratic sequences from the first values of a sequence of data, presented on a computer screen in various formats: tabular, scattered data pairs and sequential. International Journal of Science and Mathematics Education, 18(6) pp. Generalization Strategies in Finding the nth Term Rule for Simple Quadratic Sequences. Biza, Irene Hewitt, Dave Watson, Anne and Mason, John
