Trig Identities

Question 1

1/sin x

Answer 1

csc x

Question 2

1/cos x

Answer 2

sec x

Question 3

tan x = ?

Answer 3

sin x / cos x

Question 4

1/tan x

Answer 4

cot x

Question 5

cot x = ?

Answer 5

cos x / sin x

Question 6

1+ tan^2 x =?

Answer 6

sec^2 x

Question 7

1 + cot^2 x = ?

Answer 7

csc^2 x

Question 8

sin(π/2 - x) =

Answer 8

cos x

Question 9

cos(π/2 - x) =

Answer 9

sin x

Question 10

csc(π/2 - x) =

Answer 10

sec x

Question 11

sec(π/2 - x) =

Answer 11

csc x

Question 12

tan(π/2 - x) =

Answer 12

cot x

Question 13

cot(π/2 - x) =

Answer 13

tan x

Question 14

sin(-x) =

Answer 14

-sin x

Question 15

csc(-x) =

Answer 15

-csc x

Question 16

sec(-x) =

Answer 16

sec x

Question 17

cos(-x) =

Answer 17

cos x

Question 18

tan(-x) =

Answer 18

• tan x

Question 19

cot(-x) =

Answer 19

• cot x

Question 20

sin(a + b) =

Answer 20

sin a cos b + cos a sin b

Question 21

sin(a - b) =

Answer 21

sin a cos b - cos a sin b

Question 22

cos(a + b) =

Answer 22

cos a cos b - sin a sin b

Question 23

cos(a - b) =

Answer 23

cos a cos b + sin a sin b

Question 24

tan(a + b) =

Answer 24

tan a + tan b / 1 - tan a tan b

Question 25

sin 2a

Answer 25

2 sin a cos a

Question 26

cos 2a

Answer 26

cos^2 a − sin^2 a
2 cos^2 a − 1
1 − 2 sin^2 a

Question 27

tan 2a

Answer 27

2 tan a
1 − tan2 a