Question

multiple choice: write the letter of the correct answer1. convert $\frac{13pi}{15}$ to degree measure.a) $355^o$ b) $156^o$ c) $162^o$ d) $207.7^o$2. evaluate $sin \frac{11pi}{6}$.a) $-\frac{sqrt{3}}{2}$ b) $\frac{sqrt{3}}{2}$ c) $-\frac{1}{2}$ d) $\frac{1}{2}$3. convert $160^o$ to radian measure.a) $\frac{9pi}{4}$ b) $\frac{9pi}{8}$ c) $\frac{8pi}{9}$ d) $\frac{4pi}{9}$4. evaluate $cos 60^o$.a) $-\frac{sqrt{3}}{2}$ b) $\frac{sqrt{3}}{2}$ c) $-\frac{1}{2}$ d) $\frac{1}{2}$5. which of the following has the largest amplitude?a) $y = -7cos(x - 3pi) + 3$b) $y = -3sinleft(4x + \frac{pi}{2}
ight) - 6$c) $y = 2sinleft(\frac{x}{2} + 2pi
ight) + 7$d) $y = 5cosleft(6x - \frac{2pi}{3}
ight) - 2$6. what is the midline of$y = -6sin(5\theta - 9pi) + 3$a) $y = -6$ b) $y = 5$c) $y = -9$ d) $y = 3$

Explanation:

Step1: Convert degrees to radians

Multiply degrees by $\frac{\pi}{180^\circ}$.
$\text{Radians} = 160^\circ \times \frac{\pi}{180^\circ} = \frac{160\pi}{180} = \frac{8\pi}{9}$

Step2: Evaluate $\cos60^\circ$

Use known unit circle value.
$\cos60^\circ = \frac{1}{2}$

Answer:

1. C) $\frac{8\pi}{9}$
2. D) $\frac{1}{2}$