91Ó°ÊÓ

For each expression that follows, replace \(x\) with \(30^{\circ}, y\) with \(45^{\circ}\), and \(z\) with \(60^{\circ}\), and then simplify as much as possible. $$ 2 \cos \left(90^{\circ}-z\right) $$

Draw \(-270^{\circ}\) in standard position, locate a convenient point on the terminal side, and then find sine, cosine, and tangent of \(-270^{\circ}\).

If the angle of elevation to the sun is \(74.3^{\circ}\) when a flagpole casts a shadow of \(22.5\) feet, what is the height of the flagpole? a. \(63.2\) feet b. \(79.5\) feet c. \(83.1\) feet d. \(80.0\) feet

Problems 65 through 68 refer to right triangle \(A B C\) with \(C=90^{\circ}\). In each case, use a calculator to find \(\sin A, \cos A, \sin B\), and \(\cos B\). Round your answers to the nearest hundredth if necessary. \(a=3.68, c=5.93\)

These questions are available for instructors to help assess if you have successfully met the learning objectives for this section. Given right triangle \(A B C\) with \(C=90^{\circ}\), if \(a=58 \mathrm{~cm}\) and \(b=35 \mathrm{~cm}\), find \(B\). a. \(59^{\circ}\) b. \(31^{\circ}\) c. \(53^{\circ}\) d. \(37^{\circ}\)