Chapter 10 - NCPN

31. How could the identity for sin A be derived from the identity for
2
cos A Show your work. see margin
2
32. When an arrow is shot from a bow,
the distance that the arrow travels is
a function of the initial velocity and
the angle of elevation, θ. The distance
can be modeled by the function
v
d = ( ) 0 2
sinθ
cos θ, where v
16
0
is the
initial velocity of the arrow, in feet per
second.
a. Use a double angle formula to
rewrite the function in terms of the
v
double angle, 2θ. d = ( ) 2
0
sin2θ
32
b. What angle of elevation, θ, will
maximize the distance the arrow
travels for a given initial velocity
Explain. see margin
c. An arrow is shot with an angle of
elevation of 30° and an initial velocity
of 80 feet per second. How many
feet will the arrow travel Round your answer to the nearest
tenth. 173.2 ft
Mixed Review
33. In ΔPRQ, m∠P = 72°, RQ = 7 units, and PQ = 4.3 units. Find
m∠R to the nearest tenth. 35.7°
34. What is the height, h, of the attic in Jeremy’s house Round your
answer to the nearest tenth if necessary. 12.7 ft
35. Verify the trigonometric identity
check students’ work; see margin for sample
484 Chapter 10 Trigonometric Functions and Identities
cscθ
cos θ
= 1.
cot θ