Trigonometrie

Question 1

Sin(a+-b)

Answer 1

Sin a * cos b +- sin b * cos a

Question 2

Cos (a + b)
Cos (a - b)

Answer 2

Cos a * cos b - sin a * sin b
Cos a * cos b + sin a * sin b

Question 3

Sin 2x

Answer 3

2 *sin x * cos x

Question 4

Cos 2x

Answer 4

Cos^2 x - sin^2 x

2cos^2 x - 1

1- 2sin^2 x

Question 5

Sin 3x

Answer 5

3 * sin x - 4* sin^3 x

Question 6

Cos 3x

Answer 6

4 * cos^3 x - 3 * cos x

Question 7

Sin x/2

Answer 7

+- (1 - cos x) / 2 totul sub radical iar semnul depinde de cadran

Question 8

Cos x / 2

Answer 8

+- (1 + cos x)/2 totul sub radical iar semnul depinde de cadran

Question 9

Sin^2 x + cos^2 x

Answer 9

1

Question 10

Sin a + sin b

Answer 10

2 * sin (a + b)/2 * cos (a - b)/2

Question 11

Sin a - sin b

Answer 11

2 * sin (a - b)/2 * cos (a + b)/2

Question 12

Cos a + cos b

Answer 12

2 * cos (a + b)/2 * cos (a - b)/2

Question 13

Cos a - cos b

Answer 13

-2 * sin (a + b)/2 * sin (a - b)/2

Question 14

Sin x

Answer 14

Cos (pi/2 - x)

Question 15

Cos x

Answer 15

Sin (pi/2 - x)

Question 16

Sin x * sin y

Answer 16

[ cos (x - y) + cos (x + y) ] / 2

Question 17

Sin x * cos y

Answer 17

[ sin (x + y) + sin (x - y) ] / 2

Question 18

Cos x * cos y

Answer 18

[ cos (x + y) + cos (x - y) ] / 2