© Texas Instruments, 2007
Trigonometry with the TI-84 Plus Silver Edition
Trigonometric Functions
Acute Angles
ò
sin
= opp/hyp
csc
= hyp/opp
ô
cos
= adj/hyp
sec
= hyp/adj
ö
tan
= opp/adj
cot
= adj/opp
Arbitrary Angles
sin
= b/r
csc
= r/b
cos
= a/r
sec
= r/a
tan
= b/a
cot
= a/b
Real Numbers
sin t = y
csc t = 1/y
cos t = x
sec t = 1/x
tan t = y/x
cot t = x/y
Special Triangles
Trigonometric Identities
csc t = 1/sin t
tan t = sin t/cos t
sec t = 1/cos t
cot t = cos t/sin t
cot t = 1/tan t
sin
2
t + cos
2
t = 1
sin (–t) = –sin t
1 + tan
2
t = sec
2
t
cos (–t) = cos t
1 + cot
2
t = csc
2
t
tan (–t) = –tan t
sin (u + v) = sin u cos v + cos u sin v
cos (u + v) = cos u cos v – sin u sin v
tan (u + v) =
sin (u – v) = sin u cos v – cos u sin v
cos (u – v) = cos u cos v + sin u sin v
tan (u – v) =
sin 2u =2 sin u cos u
cos 2u = cos
2
u – sin
2
u = 1 – 2 sin
2
u = 2 cos
2
u – 1
tan 2u =
sin =
cos =
tan = =
tan
2
u =
sin
2
u =
cos
2
u =
sin u cos v =
1/
2
[sin (u + v) + sin (u – v)]
cos u sin v =
1/
2
[sin (u + v) – sin (u – v)]
cos u cos v =
1/
2
[cos (u + v) + cos (u – v)]
sin u sin v =
1/
2
[cos (u – v) – cos (u + v)]
opp
y
r
(a,b)
x
adj
u
u
hyp
1
1
π
4
y
t
(1,0)
t radians
(x,y)
x
=45
°
1
√
3
π
6
2
40
°
60
°
60
°
4
2
c
3
b
=30
°
π
3
=60
°
√
2
90
°
270
°
300
°
240
°
315
°
225
°
330
°
210
°
0
°
180
°
30
°
150
°
45
°
135
°
60
°
120
°
(0,1)
(1,0)
(0,-1)
(-1,0)
(
,
)
1
√
3
2
2
(
,
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
,
)
√
2
√
2
2
2
(
,
-
-
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
,
)
√
3 1
2
2
(
,
-
)
√
3 1
2 2
(
, -
)
√
3
1
2
2
(
, -
-
-
-
)
√
3
1
2
2
opp
y
r
(a,b)
x
adj
u
u
hyp
1
1
π
4
y
t
(1,0)
t radians
(x,y)
x
=45
°
1
√
3
π
6
2
40
°
60
°
60
°
4
2
c
3
b
=30
°
π
3
=60
°
√
2
90
°
270
°
300
°
240
°
315
°
225
°
330
°
210
°
0
°
180
°
30
°
150
°
45
°
135
°
60
°
120
°
(0,1)
(1,0)
(0,-1)
(-1,0)
(
,
)
1
√
3
2
2
(
,
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
,
)
√
2
√
2
2
2
(
,
-
-
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
,
)
√
3 1
2
2
(
,
-
)
√
3 1
2 2
(
, -
)
√
3
1
2
2
(
, -
-
-
-
)
√
3
1
2
2
opp
y
r
(a,b)
x
adj
u
u
hyp
1
1
π
4
y
t
(1,0)
t radians
(x,y)
x
=45
°
1
√
3
π
6
2
40
°
60
°
60
°
4
2
c
3
b
=30
°
π
3
=60
°
√
2
90
°
270
°
300
°
240
°
315
°
225
°
330
°
210
°
0
°
180
°
30
°
150
°
45
°
135
°
60
°
120
°
(0,1)
(1,0)
(0,-1)
(-1,0)
(
,
)
1
√
3
2
2
(
,
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
,
)
√
2
√
2
2
2
(
,
-
-
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
,
)
√
3 1
2
2
(
,
-
)
√
3 1
2 2
(
, -
)
√
3
1
2
2
(
, -
-
-
-
)
√
3
1
2
2
opp
y
r
(a,b)
x
adj
u
u
hyp
1
1
π
4
y
t
(1,0)
t radians
(x,y)
x
=45
°
1
√
3
π
6
2
40
°
60
°
60
°
4
2
c
3
b
=30
°
π
3
=60
°
√
2
90
°
270
°
300
°
240
°
315
°
225
°
330
°
210
°
0
°
180
°
30
°
150
°
45
°
135
°
60
°
120
°
(0,1)
(1,0)
(0,-1)
(-1,0)
(
,
)
1
√
3
2
2
(
,
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
,
)
√
2
√
2
2
2
(
,
-
-
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
,
)
√
3 1
2
2
(
,
-
)
√
3 1
2 2
(
, -
)
√
3
1
2
2
(
, -
-
-
-
)
√
3
1
2
2
tan u + tan v
1 – tan u tan v
tan u – tan v
1 + tan u tan v
2 tan u
1 – tan
2
u
1 – cos u
sin u
sin u
1 + cos u
u
2
1 – cos 2u
2
1 + cos 2u
2
u
2
1 – cos u
2
u
2
1 + cos u
2
√
√
Special Values of Trigonometric Functions
(degrees) (radians)
sin
cos
tan
cot
sec
csc
0°
0
0
1
0
–
1
–
30°
2
45°
1
1
60°
2
90°
1
0
–
0
–
1
π
6
1
2
√
3
2
√
3
3
√
3
2
√
3
3
π
4
√
2
2
√
2
2
√
2
√
2
√
3
2
1
2
√
3
√
3
3
2
√
3
3
π
2
Laws of Sines and Cosines
Sine
Cosine
sin A = sin B = sin C
a
2
= b
2
+ c
2
– 2bc cos A
a b c
c
2
= a
2
+ b
2
– 2ab cos C
b
2
= c
2
+ a
2
– 2ac cos B
Unit Circle
opp
y
r
(a,b)
x
adj
u
u
hyp
1
1
π
4
y
t
(1,0)
t radians
(x,y)
x
=45
°
1
√
3
π
6
2
40
°
60
°
60
°
4
2
c
3
b
=30
°
π
3
=60
°
√
2
90
°
270
°
300
°
240
°
315
°
225
°
330
°
210
°
0
°
180
°
30
°
150
°
45
°
135
°
60
°
120
°
(0,1)
(1,0)
(0,-1)
(-1,0)
(
,
)
1
√
3
2
2
(
,
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
, -
)
1
√
3
2
2
(
,
)
√
2
√
2
2
2
(
,
-
-
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
, -
)
√
2
√
2
2
2
(
,
)
√
3 1
2
2
(
,
-
)
√
3 1
2 2
(
, -
)
√
3
1
2
2
(
, -
-
-
-
)
√
3
1
2
2
π
3
Inverse Trigonometric Functions
Function
Domain
Range
y ?
y = sin
-1
x
–1
≤
x
≤
1
–
≤
y
≤
y @
y = cos
-1
x
–1
≤
x
≤
1
0
≤
y
≤ π
y A
y = tan
-1
x
All real numbers
– <
y
<
y = cot
-1
x
All real numbers
0 < y <
π
y = sec
-1
x
x
≥
1
0,
∪
y = csc
-1
x
x
≥
1
– , 0
∪
0,
π
2
π
2
π
2
π
2
π
2
π
2
π
2
education.ti.com
1 - cos 2u
1 + cos 2u
π
2
,
π