Question

Please help me with parts C and D, I’m struggling with them

Answer 1

`\begin{gathered} c)s\imaginaryI n(\theta)/(2)=\sqrt{(1)/(2)(1-(√(13))/(7))} \\ decimal=0.49 \\ d)cos(\theta)/(2)=\sqrt{(1)/(2)((√(13))/(7)+1)} \\ decimal=0.87 \end{gathered}`

Step-by-step explanation

Given;

`\begin{gathered} sin\theta=(6)/(7) \\ 0<\theta<(\pi)/(2) \end{gathered}`

c) Hence;

`\begin{gathered} sin(\theta)/(2)=\sqrt{(1)/(2)(1-(√(13))/(7)}) \\ \end{gathered}`

In decimal form;

`sin(\theta)/(2)=0.49`

d)

`\begin{gathered} cos\theta=(√(13))/(7) \\ cos(\theta)/(2)=\sqrt{(1)/(2)(\sqrt{(13)/(7)+1})} \\ decimal=0.87 \end{gathered}`