91Ó°ÊÓ

Use an isosceles right triangle with legs of length 3 to find the exact values of \(\sin 45^{\circ},\) \(\cos 45^{\circ},\) and \(\tan 45^{\circ} .\)

In \(3-44,\) find the exact value. $$ \cos 45^{\circ} $$

In \(3-44,\) find the exact value. $$ \sin 45^{\circ} $$

In \(8-17,\) for each angle with the given degree measure, find the measure of the reference angle. \(505^{\circ}\)

In \(18-27,\) for each given angle, find a coterminal angle with a measure of \(\theta\) such that \(0 \leq \theta < 360\). $$ 390^{\circ} $$

From a point on the ground that is 100 feet from the base of a building, the tangent of the angle of elevation of the top of the building is \(\frac{5}{4} .\) To the nearest foot, how tall is the building?

Under a reflection in the \(y\) -axis, the image of \(A(x, y)\) is \(A^{\prime}(-x, y)\) . The measure of \(\angle R O P=\theta\) and \(P(\cos \theta, \sin \theta)\) is a point on the terminal side of \(\angle R O P .\) Let \(P^{\prime}\) be the image of \(P\) and \(R^{\prime}\) be the image of \(R\) under a reflection in the \(y\) -axis. a. What are the coordinates of \(P^{\prime} ?\) b. Express the measure of \(\angle R^{\prime} O P^{\prime}\) in terms of \(\theta\) c. Express the measure of \(\angle R O P^{\prime}\) in terms of \(\theta\)

In \(3-44,\) find the exact value. $$ \cos 270^{\circ} $$

In \(3-44,\) find the exact value. $$ \sin 270^{\circ} $$

In \(3-44,\) find the exact value. $$ \csc 270^{\circ} $$