Question

I need help with this practice from my trigonometry prep book I attempted this previously, struggling, I got two answers and I’m not sure if I’m correct so I would like more clarification

Answer 1

`\begin{gathered} \tan (\alpha)=-(12)/(5) \\ \cos (\beta)=(3)/(5) \end{gathered}`
`\begin{gathered} \alpha=\tan ^(-1)(-(12)/(5))+180 \\ \beta=360-\cos ^(-1)((3)/(5)) \end{gathered}`

Therefore:

`\cos (\alpha-\beta)=-(63)/(65)`