## Monday, 11 March 2013

### Quadratic - Practice 13 (Farrell Nah)

1. 13a) The explanation is very clear and succinct and has a diagram to further help explain why the equation has real and equal roots.

13b) The explanation is also very clear although some people may not understand why the substitution is necessary.

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3. 13a) Does not mathematically show how -3k^2+2k+1=0 works out to k=-1/3 or 1, Not very organized, says b^2-4ac = 0 3 times.

13b) Concept not clear as he does not say which value of k to substitute and where it is substituted. Again, he does not show how the quadratic equation is solved. Work is organized and clear enough to understand

4. Explanation is clear for both parts of the question. No conceptual error. Answers are quite well organised.

5. The graph and so on shows me your understanding of the question. The paper can be neater and the steps can be more clearly shown.

6. Answers are clear and systematic There is no conceptual error. Explanation is alright, it can be clearer, though. However, it is quite well done. Overall, good job.

7. 13a) Clear explanation with the aid of a diagram of a graph.

13b) Good explanation, however it may be good to label by the side which value you are subbing into it.

8. Explanation is quite clear and good use of a graph

9. 13a. Clear and good explanation, no concept errors and is neat

13b. Clear and good explanation, no concept errors, work is neat.

10. - Mathematical concept is clearly shown.
- Clarity of explanation is understandable
- Organization of thoughts are shown.

11. a) Graph makes the working quite clear, it shows the link between the concept of real and equal roots and the question.

b) Simple and clear working, rather easy to understand

Generally, your working is quite well-organized and easy to understand