Mathematics 30 June 1999 Grade 12 Diploma Exam
Mathematics 30 June 1999 Grade 12 Diploma Exam
Mathematics 30 June 1999 Grade 12 Diploma Exam
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
A POSSIBLE SOLUTION<br />
Student A<br />
Student B<br />
3 x + 2 =6 x 3 x + 2 =6 x<br />
3 x + 2 6 x 3 x + 2 6 x<br />
3 2 + 2 6 2 3 –4.3 + 2 6 –4.3<br />
81 36 3 –2.3 6 –4.3<br />
≈ 0.0799 ≈ 0.00045<br />
LHS ≠ RHS<br />
∴ x = 2 is not a correct solution<br />
LHS ≠ RHS<br />
∴ x = – 4.3 is not a correct solution<br />
• Identify the error that was made by each student and state why each error leads to an<br />
incorrect answer.<br />
A POSSIBLE SOLUTION<br />
Student A<br />
Student A stated that 6 x = 3 2x which<br />
would indicate that 6 = 3 2 which is<br />
obviously not correct.<br />
Student B<br />
In the third line of their work the student<br />
did not realize that log 3 was multiplied<br />
by (x + 2), so that in line 4 they<br />
incorrectly subtracted x.<br />
9
Change language