The sine function is given by:
[tex]\sin (\theta)=\frac{opposite}{hypotenuse}[/tex]
Therefore:
[tex]\begin{gathered} \sin (\theta)=\frac{y}{r} \\ \frac{y}{r}>0 \end{gathered}[/tex]
Therefore, we can conclude the sine is positive in II quadrant.
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The cosine function is given by:
[tex]\cos (\theta)=\frac{adjacent}{hypotenuse}[/tex]
therefore:
[tex]\begin{gathered} \cos (\theta)=-\frac{x}{r} \\ -\frac{x}{r}<0 \end{gathered}[/tex]
Therefore, we can conclude the cosine is negative in II quadrant
