Graphing Parametric Functions

Help Questions

SAT Math › Graphing Parametric Functions

Questions 1 - 1

Give the period of the graph of the equation

$f(x) = \frac{4}{7} \cos \left ( \frac{3\pi x}{7} \right )$

$\frac{14}{3}$

$\frac{7}{3}$

$\frac{4}{7}$

$\frac{8}{7}$

$\frac{2}{7}$

The period of the graph of a cosine function $f(x)= A \cos Nx$ is $\frac{2 \pi}{N}$ , or $2 \pi \div N$

Since $N = \frac{3\pi}{7}$ , the period is

$2 \pi \div \frac{3\pi}{7} = \frac{2 \pi }{1}\times \frac{7} {3\pi}= \frac{14}{3}$