The terminal side of angle θ intersects the unit circle in the first quadrant at (11/23,y). What are the exact values of sinθ and cosθ?

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Answer:

Answer below on online math notes

Step-by-step explanation:

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The terminal side of an angle is the angle at the standard position. Given that the point of intersection of the terminal side of θ and the unit circle is:

[tex](\frac{11}{23},y)[/tex]. The exact values of sine and cosine are: [tex]\sin(\theta) = \frac{2\sqrt{102}}{23}[/tex] and [tex]\cos(\theta) =\frac{11}{23}[/tex]

The given parameters are represented as:

[tex](\frac{11}{23},y)[/tex]

This means that:

[tex](\cos(\theta),\sin(\theta)) = (\frac{11}{23},y)[/tex]

Using the following trigonometry identity:

[tex]\cos^2(\theta) + \sin^2(\theta) = 1[/tex]

We have:

[tex](\frac{11}{23})^2+y^2=1[/tex]

Expand fraction

[tex]\frac{121}{529}+y^2=1[/tex]

Collect like terms

[tex]y^2=1 - \frac{121}{529}[/tex]

Take LCM

[tex]y^2=\frac{529 - 121}{529}[/tex]

[tex]y^2=\frac{408}{529}[/tex]

Take square roots

[tex]y=\frac{\sqrt{408}}{23}[/tex]

Substitute value for y in [tex](\cos(\theta),\sin(\theta)) = (\frac{11}{23},y)[/tex]

[tex](\cos(\theta),\sin(\theta)) = (\frac{11}{23},\frac{\sqrt{408}}{23})[/tex]

By comparison:

[tex]\cos(\theta) =\frac{11}{23}[/tex]

[tex]\sin(\theta) = \frac{\sqrt{408}}{23}[/tex]

Expand

[tex]\sin(\theta) = \frac{\sqrt{4*102}}{23}[/tex]

Split

[tex]\sin(\theta) = \frac{\sqrt{4}*\sqrt{102}}{23}[/tex]

Because the angle is in the first quadrant, we take only positive values

[tex]\sin(\theta) = \frac{2\sqrt{102}}{23}[/tex]

So, the exact values of sine and cosine are:

[tex]\sin(\theta) = \frac{2\sqrt{102}}{23}[/tex] and [tex]\cos(\theta) =\frac{11}{23}[/tex]

Read more about terminal angles at:

https://brainly.com/question/12891381