91Ó°ÊÓ

Using Half-Angle Formulas, use the half-angle formulas to determine the exact values of the sine, cosine, and tangent of the angle. $$7 \pi / 12$$

Solving a Trigonometric Equation In Exercises \(25-38,\) find all solutions of the equation in the interval \(0,2 \pi ) .\) $$\csc x+\cot x=1$$

Using Half-Angle Formulas, (a) determine the quadrant in which \(u\) 2 lies, and (b) find the exact values of \(\sin (u\) 2), \(\cos (u\) 2), and \(\tan (u\) 2) using the half-angle formulas. $$\cos u=7 / 25, \quad 0

Use the fundamental identities to simplify the expression. There is more than one correct form of each answer. \(\sin \phi(\csc \phi-\sin \phi)\)

Verify the identity. $$(1+\sin y)[1+\sin (-y)]=\cos ^{2} y$$

Evaluating a Trigonometric Expression In Exercises \(35-40\) , find the exact value of the expression. $$ \sin 120^{\circ} \cos 60^{\circ}-\cos 120^{\circ} \sin 60^{\circ} $$

Use the fundamental identities to simplify the expression. There is more than one correct form of each answer. \(\cos t\left(1+\tan ^{2} t\right)\)

Verify the identity. $$\frac{\tan x+\tan y}{1-\tan x \tan y}=\frac{\cot x+\cot y}{\cot x \cot y-1}$$

Using Half-Angle Formulas, (a) determine the quadrant in which \(u\) 2 lies, and (b) find the exact values of \(\sin (u\) 2), \(\cos (u\) 2), and \(\tan (u\) 2) using the half-angle formulas. $$\sin u=5 / 13, \quad \pi / 2

Evaluating a Trigonometric Expression In Exercises \(35-40\) , find the exact value of the expression. $$ \cos 120^{\circ} \cos 30^{\circ}+\sin 120^{\circ} \sin 30^{\circ} $$