우수 답변
sin (theta) = a / c
csc (theta) = 1 / sin (theta) = c / a
cos (theta) = b / c
sec ( theta) = 1 / cos (theta) = c / b
tan (theta) = sin (theta) / cos (theta) = a / b
cot (theta) = 1 / tan (theta) = b / a
sin (-x) = -sin (x) csc (-x) = -csc (x) cos (-x) = cos (x) sec (-x) = sec (x) tan (-x) = -tan (x) cot (-x) = -cot (x)
sin ^ 2 (x) + cos ^ 2 (x ) = 1
tan ^ 2 (x) + 1 = 초 ^ 2 (x)
cot ^ 2 (x) + 1 = csc ^ 2 (x)
sin (xy) = sin x cos y cos x sin y
cos (xy) = cos x cos x cos x sin y
삼각법 ID
sin (theta) = a / c
csc (theta) = 1 / sin (theta) = c / a
cos (theta) = b / c
sec (theta) = 1 / cos (theta) = c / b
tan (theta) = sin (theta) / cos (theta) = a / b
cot (theta) = 1 / tan (theta) = b / a
sin (-x) = -sin (x) csc (-x) = -csc (x) cos (-x) = cos (x) sec (- x) = sec (x) tan (-x) = -tan (x) cot (-x) = -cot (x)
죄
^ 2
(x) + cos
^ 2
(x) = 1
tan
^ 2
(x) + 1 = 초
^ 2
(x)
침대
^ 2
(x) + 1 = csc
^ 2
(x)
sin (x
y) = sin x cos y
cos x sin y
cos (x
y) = cos x cosy
sin x sin y
tan (x
y) = (tan x
tan y) / (1
tan x tan y)
sin (2x) = 2 sin x cos x
cos (2x) = cos
^ 2
(x)-죄
^ 2
(x) = 2 cos
^ 2
(x)-1 = 1-2 sin
^ 2
(x)
tan (2x) = 2 tan (x) / (1- tan
^ 2
(x))
죄
^ 2
(x) = 1 / 2-1/2 cos (2x)
cos
^ 2
(x) = 1/2 + 1/2 cos (2x)
sin x-sin y = 2 sin ((x-y) / 2) cos ((x + y) / 2)
cos x-cos y = -2 sin ( (x-y) / 2) sin ((x + y) / 2)
공통 각도의 삼각 테이블
각도
0
30
45
60
90
죄
^ 2
(a)
0/4
1/4
2/4
3/4
4/4
cos
^ 2
(a)
4/4
3 / 4
2/4
1/4
0/4
tan
^ 2
(a)
0/4
1/3
2/2
3/1
4/0
Answer
-cot (x)
Cot x는 이상한 함수이므로 x를 -x로 바꾸면 함수의 부호