Trig Identities

Question 1

tan(x)

Answer 1

sin(x)/cos(x)

and 1/cot(x)

Question 2

cot(x)

Answer 2

cos(x)/sin(x)

Question 3

csc(x)

Answer 3

1/sin(x)

Question 4

sin(x)

Answer 4

1/csc(x)

Question 5

sec(x)

Answer 5

1/cos(x)

Question 6

cos(x)

Answer 6

1/sec(x)

Question 7

cot(x)

Answer 7

1/tan(x)

Question 8

sin^2(x)+cos^2(x)

Answer 8

1

Question 9

tan^2(x)+1

Answer 9

sec^2(x)

Question 10

1+cot^2(x)

Answer 10

csc^2(x)

Question 11

sin(-x)

Answer 11

-sin(x)

Question 12

cos(-x)

Answer 12

cos(x)

Question 13

tan(-x)

Answer 13

-tan(x)

Question 14

sin(2x)

Answer 14

2sin(x)cos(x)

Question 15

cos(2x)

Answer 15

cos^2(x)-sin^2(x)
2cos^2(x)-1
1-2sin^2(x)

Question 16

tan(2x)

Answer 16

2tan(x)/1-tan^2(x)

Question 17

sin(x/2)

Answer 17

+-√1-cos(x)/2

Question 18

cos(x/2)

Answer 18

+-√1+cos(x)/2

Question 19

tan(x/2)

Answer 19

+-√1-cos(x)/1+cos(x)

Question 20

sin(x+-y)

Answer 20

sin(x)cos(y)+cos(x)sin(y)

Question 21

cos(x+-y)

Answer 21

cos(x)cos(y)-+sin(x)sin(y)

Question 22

tan(x+-y)

Answer 22

tan(x)+-tan(y)/1-+tan(x)tan(y)