Find Amplitude, Period, and Phase Shift y=3/4cos(6x)

$y = \frac{3}{4} \cos (6 x)$

Use the form $a \cos (b x - c) + d$ to find the variables used to find the amplitude, period, phase shift, and vertical shift.

$a = \frac{3}{4}$

$b = 6$

$c = 0$

$d = 0$

Find the amplitude $| a |$ .

Amplitude: $\frac{3}{4}$

Find the period of $\frac{3 \cos (6 x)}{4}$ .

The period of the function can be calculated using $\frac{2 π}{| b |}$ .

$\frac{2 π}{| b |}$

Replace $b$ with $6$ in the formula for period.

$\frac{2 π}{| 6 |}$

The absolute value is the distance between a number and zero. The distance between $0$ and $6$ is $6$ .

$\frac{2 π}{6}$

Cancel the common factor of $2$ and $6$ .

Factor $2$ out of $2 π$ .

$\frac{2 (π)}{6}$

Cancel the common factors.

Factor $2$ out of $6$ .

$\frac{2 π}{2 \cdot 3}$

Cancel the common factor.

$\frac{2 π}{2 \cdot 3}$

Rewrite the expression.

$\frac{π}{3}$

Find the phase shift using the formula $\frac{c}{b}$ .

The phase shift of the function can be calculated from $\frac{c}{b}$ .

Phase Shift: $\frac{c}{b}$

Replace the values of $c$ and $b$ in the equation for phase shift.

Phase Shift: $\frac{0}{6}$

Divide $0$ by $6$ .

Phase Shift: $0$

List the properties of the trigonometric function.

Amplitude: $\frac{3}{4}$

Period: $\frac{π}{3}$

Phase Shift: None

Vertical Shift: None