Question

What is the value of sinθ given that (3, −7) is a point on the terminal side of θ?

Answer 1

`\begin{gathered} \text{ using pythagoras theorem} \\ \\ OB=√(OA^2+AB^2)=√(3^2+7^2)=√(58) \\ \\ \Rightarrow\sin\theta=(AB)/(OB)=-(7)/(√(58))=-(7√(58))/(58) \end{gathered}`