Trig Identities & Equations

Question 1

sin(180-x)

Answer 1

sinx

Question 2

cos(-x)

Answer 2

cosx

Question 3

sin30

Answer 3

0.5

Question 4

sin45

Answer 4

(2)^-0.5

Question 5

sin60

Answer 5

(3)^0.5/2

Question 6

cos30

Answer 6

(3)^0.5/2

Question 7

cos45

Answer 7

(2)^-0.5

Question 8

cos60

Answer 8

0.5

Question 9

tan30

Answer 9

(3)^-0.5

Question 10

tan45

Answer 10

1

Question 11

tan60

Answer 11

(3)^0.5

Question 12

tan90

Answer 12

Undefined

Question 13

(sinx)^2 + (cosx)^2 = ?

Answer 13

1

Question 14

tanx = a/b

Answer 14

a = sinx
b = cosx

Question 15

1/cosx

Answer 15

secx

Question 16

1/sinx

Answer 16

cosecx

Question 17

1/tanx

Answer 17

cotx

cosx/sinx

Question 18

sin(a+b)

Answer 18

sin(a)cos(b) + cos(a)sin(b)

Question 19

cos(a+b)

Answer 19

cos(a)cos(b) - sin(a)sin(b)

Question 20

tan(a+b)

Answer 20

(tan(a) + tan(b))/(1 -tan(a)tan(b))

Question 21

sin2x

Answer 21

2sin(x)cos(x)

Question 22

cos(2x)

Answer 22

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

Question 23

tan2x

Answer 23

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