Question 12
Observation
This question was also reported to be attempted by majority of the candidates. According to the report, while majority of them were able to complete the table of values, a little less were able to draw the graph using the given scales. Majority of them were reported not to have attempted the questions that followed the graph. Teachers were encouraged to emphasize reading from graphs during instruction so that their performance may improve in subsequent examinations. Candidates were expected to obtain the following table:
X |
0o |
30o |
60o |
90o |
120o |
150o |
180o |
210o |
240o |
270o |
300o |
330o |
360o |
y |
2.0 |
3.2 |
3.6 |
3.0 |
1.6 |
- 0.2 |
-2.0 |
-3.2 |
-3.6 |
-3.0 |
-1.6 |
0.2 |
2.0 |
Using the table and the given scales, candidates would draw the graph of y = 3sin x + 2cos x for 0o ≤ x ≤ 360o as shown below:
