91Ó°ÊÓ

determine whether the statement is true or false. Justify your answer. $$\tan a=\tan (a-6 \pi)$$

Sketch the graph of the function. (Include two full periods.) $$y=2-\sin \frac{2 \pi x}{3}$$

Use trigonometric identities to transform the left side of the equation into the right side \((0<\theta<\pi 2)\). $$(\sec \theta+\tan \theta)(\sec \theta-\tan \theta)=1$$

Finding the Central Angle Find the radian measure of the central angle of a circle of radius \(r\) that intercepts an are of length \(s\). \(r=80\) kilometers, \(s=150\) kilometers

For the simple harmonic motion described by the trigonometric function, find (a) the maximum displacement, (b) the frequency, (c) the value of \(d\) when \(t=5,\) and (d) the least positive value of \(t\) for which \(d=0 .\) Use a graphing utility to verify your results. $$d=9 \cos \frac{6 \pi}{5} t$$

Use a graph to solve the equation on the interval \(-2 \pi, 2 \pi\). $$\sec x=-2$$

Evaluate the sine, cosine, and tangent of the angle without using a calculator. $$300^{\circ}$$

Finding the Central Angle Find the radian measure of the central angle of a circle of radius \(r\) that intercepts an are of length \(s\). \(r=14\) feet \(, s=8\) feet

Use a graph to solve the equation on the interval \(-2 \pi, 2 \pi\). $$\sec x=2$$

Use trigonometric identities to transform the left side of the equation into the right side \((0<\theta<\pi 2)\). $$\sin ^{2} \theta-\cos ^{2} \theta=2 \sin ^{2} \theta-1$$