Question

PLEASE HELP....!!!!!! Need answer ASAP, so confused

Answer 1

Answer:

$b. \ y=3cos(3\theta)$

Step-by-step explanation:

The cosine function is a trigonometric function whose curve is symmetric with respect to the y-axis, hence this function is said to be even. This function has the following form:

$y=acos(b \theta)$

The amplitude of the plotted graph is 3 that represents half the distance  between the maximum and minimum values. Since at x = 0, y = 3, this y-value is the value of a. On the other hand, the period, which is the length of one cycle of the curve, can be found as $T=\frac{2\pi}{3}$ and:

$T=\frac{2\pi}{b} \therefore b=\frac{2\pi}{T}=\frac{2\pi \times 3}{2\pi}=3$

Finally:

$\boxed{y=3cos(3\theta)}$