TRIGONOMETRY: A UNIT CIRCLE APPROACH
12TH EDITION
CHAPTER 1. GRAPHS AND FUNCTIONS
Section 1.1 (f) Quadrant IV
1. 0
2. 5 3 8 8
3. 32 42 25 5
4. 112 602 121 3600 3721 612
Since the sum of the squares of two of the sides
of the triangle equals the square of the third side,
the triangle is a right triangle.
1 16. (a) Quadrant I
5. bh
2 (b) Quadrant III
(c) Quadrant II
6. true (d) Quadrant I
7. x-coordinate or abscissa; y-coordinate or (e) y-axis
ordinate (f) x-axis
8. quadrants
9. midpoint
10. False; the distance between two points is never
negative.
11. False; points that lie in Quadrant IV will have a
positive x-coordinate and a negative y-coordinate.
The point 1, 4 lies in Quadrant II.
17. The points will be on a vertical line that is two
x x y y2
12. True; M 1 2 , 1 units to the right of the y-axis.
2 2
13. b
14. a
15. (a) Quadrant II
(b) x-axis
(c) Quadrant III
(d) Quadrant I
(e) y-axis
,18. The points will be on a horizontal line that is
three units above the x-axis. 28. d ( P1 , P2 ) 6 ( 4) 2 2 (3) 2
102 52 100 25
125 5 5
29. d ( P1 , P2 ) 2.3 (0.2) 2 1.1 (0.3) 2
2.52 0.82 6.25 0.64
6.89 2.62
30. d ( P1 , P2 ) 0.3 1.2 2 1.1 2.32
19. d ( P1 , P2 ) (2 0) 2 (1 0) 2 (1.5) 2 (1.2) 2 2.25 1.44
22 12 4 1 5 3.69 1.92
20. d ( P1 , P2 ) (2 0) 2 (1 0) 2 31. d ( P1 , P2 ) (0 a) 2 (0 b) 2
(2) 2 12 4 1 5 ( a ) 2 ( b ) 2 a 2 b 2
21. d ( P1 , P2 ) (2 1) 2 (2 1) 2 32. d ( P1 , P2 ) (0 a ) 2 (0 a) 2
(3) 2 12 9 1 10 (a )2 (a )2
a 2 a 2 2a 2 a 2
22. d ( P1 , P2 ) 2 (1) 2
(2 1) 2
33. A (2,5), B (1,3), C (1, 0)
32 12 9 1 10
d ( A, B ) 1 (2) 2 (3 5)2
23. d ( P1 , P2 ) (5 3) 2 4 4
2
32 (2) 2 9 4 13
22 8 4 64 68 2 17 1 12 (0 3)2
2
d ( B, C )
(2) 2 (3)2 4 9 13
2 1 4 0
2 2
24. d ( P1 , P2 )
d ( A, C ) 1 (2) 2 (0 5)2
3 2
4 9 16 25 5
2
12 (5) 2 1 25 26
25. d ( P1 , P2 ) 4 (7) 2 (0 3)2
112 ( 3) 2 121 9 130
26. d ( P1 , P2 ) 4 2 2 2 (3) 2
22 52 4 25 29
27. d ( P1 , P2 ) (6 5) 2 1 (2)
2
12 32 1 9 10
, Verifying that ∆ ABC is a right triangle by the d ( A, B)2 d ( B, C )2 d ( A, C )2
Pythagorean Theorem:
10 2 10 2
2 2
d ( A, B)2 d ( B, C )2 d ( A, C )2 20
2
13 13 200 200 400
2 2 2
26
400 400
13 13 26 1
26 26 The area of a triangle is A bh . In this
2
1 problem,
The area of a triangle is A bh . In this
2
A d ( A, B ) d ( B, C )
1
problem, 2
A 1 d ( A, B) d ( B, C ) 1
10 2 10 2
2 2
1 13 13 1 13 1
100 2 100 square units
2 2 2
13
2 square units
35. A ( 5,3), B (6, 0), C (5,5)
34. A (2, 5), B (12, 3), C (10, 11) d ( A, B) 6 ( 5) 2 (0 3)2
d ( A, B ) 12 (2) 2 (3 5)2 112 ( 3) 2 121 9
142 (2) 2 130
196 4 200 d ( B, C ) 5 6 2 (5 0)2
10 2 (1) 2 52 1 25
d ( B, C ) 10 12 2 (11 3)2 26
(2) (14)
2 2
d ( A, C ) 5 ( 5) 2 (5 3)2
4 196 200 102 22 100 4
10 2 104
d ( A, C ) 10 (2) 2
(11 5) 2
2 26
122 (16) 2
144 256 400
20
Verifying that ∆ ABC is a right triangle by the
Pythagorean Theorem:
Verifying that ∆ ABC is a right triangle by the
Pythagorean Theorem:
, d ( A, C )2 d ( B, C )2 d ( A, B)2 d ( A, C )2 d ( B, C )2 d ( A, B)2
2
2 2 2 2 2 2
104 26 130 29 29 145
104 26 130 29 4 29 145
130 130 29 116 145
1
The area of a triangle is A bh . In this 145 145
2 1
problem, The area of a triangle is A bh . In this
2
A d ( A, C ) d ( B, C )
1 problem,
2
A d ( A, C ) d ( B, C )
1
1
104 26 2
2 1
1 29 2 29
2 26 26 2
2 1
1 2 29
2 26 2
2 29 square units
26 square units
37. A (4, 3), B (0, 3), C (4, 2)
36. A (6, 3), B (3, 5), C (1, 5)
d ( A, B) (0 4) 2 3 (3)
2
d ( A, B) 3 (6) 2
(5 3) 2
( 4)2 02 16 0
92 (8) 2 81 64
16
145
4
d ( B, C ) 1 32 (5 (5))2 d ( B, C ) 4 0 2 2 (3) 2
(4) 2 102 16 100
42 52 16 25
116 2 29
41
d ( A, C ) 1 ( 6) 2
(5 3) 2
d ( A, C ) (4 4) 2 2 (3)
2
52 22 25 4
02 52 0 25
29
25
5
Verifying that ∆ ABC is a right triangle by the
Pythagorean Theorem:
Verifying that ∆ ABC is a right triangle by the
Pythagorean Theorem: