Trigonometry

Question 1

cos² + sin² = ?

Answer 1

1

Question 2

cos(-x) = ?

Answer 2

cos(x)

Question 3

sin(-x) = ?

Answer 3

-sin(x)

Question 4

cos(π + x) = ?

Answer 4

-cos(x)

Question 5

sin(π + x) = ?

Answer 5

-sin(x)

Question 6

cos(π/2 - x) = ?

Answer 6

sin(x)

Question 7

sin(π/2 - x) = ?

Answer 7

cos(x)

Question 8

cos(π/2 + x) = ?

Answer 8

-sin(x)

Question 9

sin(π/2 + x) = ?

Answer 9

cos(x)

Question 10

cos(0) = ?

Answer 10

1

Question 11

sin(0) = ?

Answer 11

0

Question 12

cos(π/6) = ?

Answer 12

√3/2

Question 13

sin(π/6) = ?

Answer 13

1/2

Question 14

cos(π/4) = ?

Answer 14

√2/2

Question 15

sin(π/4) = ?

Answer 15

√2/2

Question 16

cos(π/3) = ?

Answer 16

1/2

Question 17

sin(π/3) = ?

Answer 17

√3/2

Question 18

cos(π/2) = ?

Answer 18

0

Question 19

sin(π/2) = ?

Answer 19

1

Question 20

cos u = cos v implies ….

Answer 20

u = v + 2kπ
OR
u = -v + 2kπ

Question 21

sin u = sin v implies ….

Answer 21

u = v + 2kπ
OR
u = π-v + 2kπ

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

sin(a+b) = ?

Answer 24

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

Question 25

sin(a-b) = ?

Answer 25

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

Question 26

cos(2*a) = ? (3 forms)

Answer 26

1) cos²(a) - sin²(a)
2) 1 - 2sin²(a)
3) 2cos²(a) - 1

Question 27

sin(2*a) = ?

Answer 27

2sin(a)cos(a)

Question 28

cos²(a) = f(cos(2*a))

Answer 28

(1 + cos(2*a)) / 2

Question 29

sin²(a) = f(sin(2*a))

Answer 29

(1 - cos(2*a)) / 2

Question 30

cos(a)*cos(b) = ?

Answer 30

1/2*[cos(a+b) + cos(a-b)]

Question 31

sin(a)*sin(b) = ?

Answer 31

1/2*[cos(a-b) - cos(a+b)]

Question 32

sin(a)*cos(b) = ?

Answer 32

1/2*[sin(a+b) + sin(a-b)]