15) Find the value of \( \sin \left(\frac{5 \pi}{3}\right) \) a) \( -\frac{\sqrt{3}}{2} \) b) \( \frac{1}{2} \) c) \( \frac{\sqrt{3}}{2} \) d) \( 0-\frac{1}{2} \)

If \( \tan \theta=-\frac{3}{8} \), which expression is equivalent to \( \cot \theta ? \) \( \frac{1}{-\frac{3}{8}} \) \( -\frac{3}{8}+1 \) \( \sqrt{1+\left(-\frac{\theta}{3}\right)^{2}} \) \( \left(-\frac{3}{8}\right)^{2}+1 \)

Which Pythagorean identity is correct? \( \begin{array}{l}\sin ^{2}(\theta)+1=\cos ^{2}(\theta) \\ \tan ^{2}(\theta)+1=\sec ^{2}(\theta) \\ 1-\cot ^{2}(\theta)=\csc ^{2}(\theta) \\ 1-\cos ^{2}(\theta)=\tan ^{2}(\theta)\end{array} \)

The point \( \left(-\frac{\sqrt{2}}{2}, \frac{\sqrt{2}}{2}\right) \) is the point at which the terminal ray of angle \( \theta \) intersects the unit circle. What are the values for the \( \operatorname{cosine} \) and cotangent functions for angle \( \theta \) ? \( \cos \theta=-\frac{\sqrt{2}}{2}, \cot \theta=-1 \) \( \cos \theta=\frac{\sqrt{2}}{2}, \cot \theta=1 \) \( \cos \theta=\frac{\sqrt{2}}{2}, \cot \theta=-\frac{1}{2} \) \( \cos \theta=-\frac{\sqrt{2}}{2}, \cot \theta=\frac{1}{2} \)

Based on Pythagorean identities, which equation is true? \( \begin{array}{l}\sin ^{2} \theta-1=\cos ^{2} \theta \\ \sec ^{2} \theta-\tan ^{2} \theta=-1 \\ -\cos ^{2} \theta-1=-\sin ^{2} \theta \\ \cot ^{2} \theta-\csc ^{2} \theta=-1\end{array} \)

Three trigonometric functions for a given angle are shown below. \( \sin \theta=-\frac{77}{85}, \cos \theta=\frac{36}{85}, \tan \theta=-\frac{77}{36} \) What are the coordinates of point \( (x, y) \) on the terminal ray of angle \( \theta \), assuming that the values above were not simplified? \( (-77,-36) \) \( (-77,36) \) \( (-36,77) \) \( (36,-77) \)