16 A student argues that when a rational number is multiplied by an irrational number the result will always be an irrational number.
16
- Identify the rational number for which the student's argument is not true.
16
- Prove that the student is right for all rational numbers other than the one you have identified in part (a).
[0pt]
[4 marks]
\(17 \quad \mathrm { f } ( x ) = \sin x\)
Using differentiation from first principles find the exact value of \(f ^ { \prime } \left( \frac { \pi } { 6 } \right)\)
Fully justify your answer.
[0pt]
[6 marks]
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