1. Grafique un periodo de las siguientes funciones: \( a) y=\operatorname{sen}(2 \pi x) \) b) \( y=3 \cos (2 x) c) y=4 \operatorname{sen}((3 x) d) \) \( y=\cos (x / 4) \)

3. Du vet att \( \boldsymbol{\operatorname { c o s }} \mathbf{v}=\mathbf{0 , 5 5} \). Beräkna vinkeln.

19 Multiple Choice 1 point Find the exact value \( \cos \left(\tan ^{-1} \frac{8}{15}-\cos ^{-1} \frac{3}{5}\right) \) \( \frac{77}{85} \) \( -\frac{8}{85} \) \( \frac{8}{85} \) \( -\frac{77}{85} \)

...f \( (\mathrm{x})=0,5 \sin (\mathrm{x}) \) parallel zur Gerade \( \mathrm{y}=-0,25 \mathrm{x}+3 \) ? \( \square 0 \quad \square \frac{\pi}{3} \square 0,5 \pi \quad \square \frac{2}{3} \pi \) \( \square \pi \quad \square \frac{1}{3} \pi \quad \square 1,5 \pi \quad \square 1 \frac{2}{3} \pi \)

Question From the observation deck of a skyscraper, Bentley measures a \( 48^{\circ} \) angle of depression to a ship in the harbor below. If the observation deck is 969 feet high, what is the horizontal distance from the base of the skyscraper out to the ship? Round your answeir to the nearest tenth of a foot if necessary.

3. Du vet att \( \boldsymbol{\operatorname { c o s }} \mathbf{v}=\mathbf{0 , 5 5} \). Beräkna vinkeln.