Use FOIL:
33 . D
The two right triangles are congruent 3-4-5s.
Sine is opposite over hypotenuse, so and I is true. Tangent is
opposite over adjacent, so and and II is not true.
Cosine is adjacent over hypotenuse and sine is opposite over
hypotenuse, so and and III is true.
34 . E
To find the volume of the sphere, you need the radius, which is the same
as the radius of the semicircle. Find the x-intercepts—that is, the points
at which y = 0:
The distance between the x-intercept points is the diameter, so diameter
= 6 and radius = 3. Now plug r = 3 into the sphere volume formula: